At-home ovulation tests, also known as ovulation predictor kits (OPKs), help determine when your best chances of getting pregnant are. Technically, it helps pinpoint when a female is going to release an egg that could be fertilized, a period known as ovulating.
While you don’t need to use an OPK when you’re trying to conceive, zeroing in on your 24 to 48-hour ovulation window dramatically increases your chances of getting pregnant.
First, a quick bio lesson: During a female’s menstrual cycle, one ovary releases an egg. As the egg develops, it secretes estrogen. As this hormone level rises, that signals to your pituitary gland that the egg is ready to be fertilized, Tia Jackson-Bey, MD, MPH, an OB-GYN, reproductive endocrinologist, and infertility specialist at RMA of New York in Brooklyn told Insider. The pituitary gland then increases the amount of luteinizing hormone (LH) it releases.
For most women, this surge in LH marks the one or two days they’re most fertile during their cycle. Anywhere from 24 to 48 hours after the LH surge, ovulation occurs (most often, it’s 36 hours after). Your full fertile window is made up of the five days before ovulation and the day of ovulation itself.
At-home ovulation tests generally work by monitoring the amount of LH in your urine, although some also measure estrogen metabolites in urine. Some tests can be urinated on directly (midstream tests), while others are meant to be dipped in urine (dipsticks or dip strips).
When LH reaches a certain threshold — which indicates you’re ovulating and an egg is ready to be fertilized — your test shows a positive result. This comes as either an objective result — a digital “yes” or “no,” or a smiley face or other symbol indicating a positive result — or subjective results, which usually involves judging if your test line is darker, and how much darker, than the control line.
As someone trying to get pregnant myself, I’ve used at-home ovulation tests for a while. I often turned to the less expensive tests that come in large packs, but after my fertility doctor mentioned it’d be worth investing in some of the higher-end options for quality and ease-of-use, I got curious about how different OPKs stack up against each other. (FWIW, the docs I spoke with for this piece said price doesn’t actually reflect quality.)
For this guide, I tested a variety of OPKs over the course of one menstrual cycle. As part of ongoing fertility testing, I was having ultrasounds during that cycle which confirmed when I was ovulating — so in addition to evaluating how easy the tests were to use and interpret, I also was able to test how accurate the tests were for me individually.
At the end of this guide, I go into more detail on how I tested these kits, who should use an OPK, what to look for in a test, and other FAQs about at-home ovulation tests.
The best overall
Pros: Results are easy-to-read, choice of dipstick or mid-stream test, objective results are clearer to interpet, provides more warning before ovulation than other tests
Cons: Slightly pricy
To use the Clearblue Ovulation Test, you plug a single-use test wand into the reader. Then, you either urinate on the tip of the test wand or dip it into a cup of collected urine — your choice, which is a nice feature.
After that, the reader will give you your results within 5 minutes. Instead of seeing just a positive or negative result, you’ll see a more helpful empty circle for “low fertility,” a flashing smiley face for “high fertility,” and a solid smiley face for “peak fertility.” This clarity of results, which didn’t involve having to deduce just how dark the test line is like with other dipstick OPKs, was one of my favorite things about the Clearblue Advanced Digital Ovulation test.
Unlike most standard OPKs, this test measures both LH and estrogen metabolites. The flashing smiley face is displayed when estrogen is rising, and the solid smiley face is displayed when LH has surged. For me, that meant that I had three days of “warning” (in the form of a flashing smiley face) before I got the solid smiley face (though every female’s cycle is different, so the numbers will vary for other people.)
More warning before ovulation means more chances to try to get pregnant (you want the sperm waiting in your uterus and/or fallopian tube before the egg drops, Dr. Jackson-Bey says), and ultimately more information about what’s happening during your cycle.
The only potential downsides: The process of plugging in the wand can be a little fiddly, and if it becomes dislodged during the test process you might have to discard the wand start over with the test (you get 20 in one pack). But once you get the hang of it, it’s simple to use. Also, the lowest price I could find for this test was $34 for one, reusable reader and 20 test wands. That’s a pretty good deal for a digital test, but it’s definitely more expensive than low-tech options.
Clearblue also makes a “connected” version of the test reader, which connects to an app via Bluetooth. With this, you can track your results over the course of the month and see them all in one place. This feature, which most test apps have, allows you to see patterns in your ovulation and better predict when your window will be next month. I also tested the connected version and liked it, but it requires a little more setup to get it connected to your phone, and overall I preferred the ease of the non-connected version. That said, people who want to be able to track their results over time might like that feature.
The best on a budget
The [email protected] Ovulation Test Kit comes in a pack of 100, displays clear test lines, and has a corresponding app.
Pros: Inexpensive, displays clear test lines, easy to use, app works well
Cons: Subjective interpretation
Especially for those who have been trying to get pregnant for many months or years, it can be frustrating to spend a lot of money on at-home ovulation tests. Plus, experts interviewed for this article emphasized that less-expensive tests typically work just as well as the more expensive ones. The fact that [email protected] is a little over 20 cents per tests is its first huge pro.
What’s more, of the budget tests I tried, many had relatively faint lines, even when positive, making it confusing to try to interpret the results. The [email protected] test generally displayed darker test lines compared to others. This made it easier to interpret results when comparing the test and control lines. Additionally, since the line becomes darker the closer you get to peak fertility, this higher contrast made it easier to compare tests from different days to confirm you’ve moved from low to high fertility, or high to peak.
While most of the tests in this guide have corresponding apps to help with interpretation, their quality ranges from very helpful to quite finicky. Ultimately I found many of them more confusing than useful. However, [email protected]‘s app is one of the better ones, as it allows you to photograph your test and generate an estimate whether you’re at low, high, or peak fertility. Even though this test ranks best for high-contrast lines, the app offers a nice alternative to hanging on to all your tests to compare them to each other and track your LH rise. One tip for making the most of the app: Take photos of your tests in the same lighting each day. This way, the app is better able to read and compare the results accurately.
The best midstream
The Natalist Ovulation Test makes urine collection mess-free and has clearly labeled test and control lines.
Pros: Easy to collect urine sample, interpretation is simple
Cons: Relatively expensive, some people may prefer dipsticks
I didn’t want to like a midstream ovulation test. I’ve always preferred to use tests that you dip in a collected cup of urine rather than having to urinate on them directly, and felt sure that the former was markedly easier to use. But the Natalist Ovulation Test not only proved me wrong, but also made me question why I’d never used them before.
The Natalist test is clearly carefully designed. It’s long enough so that collecting a urine sample doesn’t require sticking your whole hand in the toilet. The test case displays a tiny “T” next to the test line and a “C” next to the control line. I found that really useful, as not all tests label the lines clearly, and it can be a little confusing when you go to read the results.
I also love that even though Natalist’s tests use a plastic casing, the company itself is 100% plastic-neutral; for every pound of plastic it sells, it facilitates the removal of a pound of plastic pollution.
FWIW, Natalist is also coming out with dipstick tests, which will be available in March at Target and on Natalist’s website. I tested this as well and liked it. It’s sold in a pack with a reusable silicone urine collection cup (so nice!) and an organizer where test strips can be stored for easy tracking throughout the month.
The best for people with PCOS
The Proov Predict & Confirm Kit allows you to test for LH leading up to ovulation, and test for progesterone metabolites afterwards.
Pros: Includes LH and PdG tests
Cons: On the expensive side, not everyone needs PdG tests
This ovulation-predictor kit is a little different from the others: The tests work just like any other dip strip and are easy to use. But in addition to 15 LH strips, this kit comes with five tests that look for PdG in your urine, which is a metabolite of progesterone.
Progesterone rises after ovulation and then drops again before your period starts. Fertility doctors will often perform a blood test to check progesterone levels seven days after ovulation. If the level is high enough, you know you did indeed go through ovulation this month. Proov’s Predict and Confirm kit has you measure your LH surge to pinpoint ovulation, then check your progesterone levels on days 7, 8, 9, and 10 post-LH surge. (You also take a PdG test at the beginning of your cycle when progesterone is low, so you have something to compare your later results to, since each person’s “negative” result is a bit different.)
This is helpful for a few reasons: First, low progesterone after ovulation is associated with a higher risk of miscarriage, and it’s an important hormone for fertility. So getting a better idea of your progesterone levels can be valuable, particularly if you’re having trouble getting pregnant.
Also, people with PCOS may get unclear LH surge results (find out more in who should use an ovulation test). Testing for progesterone after you think you’ve ovulated can help you get a better idea of whether you actually did or not. This can provide insight for identifying ovulation in future cycles and is helpful information to bring to your doctor.
In terms of how the urine tests compare to a progesterone blood test, Proov says that its test strips are designed to measure PdG at the 5 ug/ml level, which has been shown to correlate to 10 ng/ml progesterone in blood. This number, 10 ng/ml, is widely accepted as the minimum threshold of progesterone needed to support conception. That said, the brand does acknowledge that urine tests aren’t a direct substitute for blood tests.
I’ve had my progesterone levels tested so I know I have healthy levels. When I took the PdG tests from the Proov kit, I got positive results at the appropriate days during my cycle.
It’s worth noting that some physicians aren’t totally sold on the idea of testing for progesterone at home. “If you’re just doing it on your own and not in conjunction with a physician or provider’s recommendations, it could be a little bit frustrating to know how to use the information,” Dr. Jackson-Bey said. “So I would just say, proceed with caution, if there are any questions at all, definitely see a provider.”
She has a point, but if you have suspicions that you have low progesterone or you’re unsure whether you’re ovulating, this test kit could be a worthwhile option as a first step before seeing a specialist, especially if you don’t have insurance or easy access to a doctor.
The best to interpret without an app
The Modern Fertility Ovulation Test is a dip strip that comes with an interpretation guide on each individual package.
Pros: Interpretation guide makes results easy, great app
Cons: Pricier than other dip strips
After you’ve tested a significant number of ovulation dipstick tests, they start to feel very similar to one another. But one thing that really stood out about Modern Fertility’s tests was that the interpretation guide is printed right on each test package. You can line your test up with the packaging and determine whether your result is low, high, or peak. It’s so simple — and so smart — that I wonder why all test manufacturers don’t do this.
Modern Fertility’s OPKs also work well with the company’s app if you prefer digital interpretation and results tracking, but to me the biggest advantage of this kit is that you won’t need technology to interpret the results. However, the brand does have a community feature on the app, where customers can ask questions which are then answered by a panel of affiliated doctors and fertility experts.
The main downside of these is at approximately 80 cents per test, these strips are more expensive than some of the comparable options I tested.
What else I tested
What else we recommend
- Femometer Ovulation Test Strips ($10.99 for 50): These strips worked just fine, but I found them a little harder to read than comparable strips because the test and control lines were overall faint. You really can’t beat the price, though, so these are still a solid option for people comfortable with less clear-cut answers.
- Stix Ovulation Tests ($17.00 for 7 tests): These midstream tests are much smaller than the Natalist ones, which might make them a good choice for anyone who has to test away from home, perhaps because of work or travel. I found the small size convenient, but also a little harder to urinate on.
- Pearl Fertility Kit ($39.99 for 15 FSH tests, 15 LH tests, and 2 hCG (pregnancy) tests): This kit involves more days of testing, and you really need to use the app to interpret the results. I found that, and the fact that you have to wait 15 minutes for results, a bit inconvenient. But if you want more details on what’s happening during your menstrual cycle, this kit could be worth a try.
What we’re looking forward to testing
There are a couple of products that I couldn’t get my hands on in time to test for this article. I’ll be trying them out in the next month and will update this post accordingly:
- First Response ($29.11 for 7 ovulation tests and 1 pregnancy test): I wanted to try these because I know the brand’s pregnancy tests are really well-regarded. Unfortunately they seem to be sold out at most retailers, and the places that had them in stock were only selling them combined with pregnancy tests.
- Wondfo One Step Ovulation (LH) Test Strips ($14.94 for 50 test strips): These are favorites on fertility message boards because of their super low price. I look forward to seeing how they compare to the other budget options I tested.
How I test OPKs
I used each test considered for this guide from at least days 12 to 19 of my menstrual cycle. (Some of the tests required more or different days of testing per their instructions.) As part of ongoing fertility testing, I had my ovulation progress monitored via ultrasound during this time, so I was able to pinpoint the day I ovulated, and observe how it lined up with the OPK test results I received. Here’s what I looked for as I tried out each ovulation test kit:
Ease of use: When using each test, I evaluated how easy it was to open the package, collect and apply a urine sample, and do any necessary assembly. The tests featured here were all simple to use and left minimal room for user error in the process.
Ease of interpreting results: To evaluate how clear the results of each test were, I looked at whether they came as an objective positive or negative, or were subjective and open to user-interpretation. For subjective tests — ones where the user has to make a judgement about how dark the test line is compared to the control line — I also evaluated how thoroughly the test instructions explained how to interpret results. I also looked at how clear the difference was between a positive result and negative result, in terms of the strength of the test and control lines. The tests that were easy to interpret and provided more detailed instructions on interpretation earned higher rankings.
Accuracy of LH surge days: All of the products tested for this article provided me a positive result two days before what my doctor judged to be my ovulation day. Because of that, I judged all of the tests as equally accurate. However, some tests indicated that LH was rising sooner than others via darkened test lines and/or “high fertility” days. Tests that provided more warning for impending ovulation received higher rankings.
What to look for in an at-home ovulation test
Cost: Price is a big factor in choosing the ovulation test that’s right for you, Dr. Jackson-Bey said. “If you’re just starting to try, it’s okay to use a cheap brand.” At the same time, there’s a lot of anxiety around trying to get pregnant, and the stakes feel high. “If you want something that’s a little bit more user-friendly, you can use the more expensive ones, but just know that there’s no difference in what they’re detecting,” she added.
Ease of use: Usually, the biggest difference between expensive and inexpensive OPKs comes down to ease of use. The more expensive options tend to be easier to interpret and have more detailed instructions; the less expensive ones still work just as well, you just have to figure some things out for yourself.
Accuracy: Dr. Jackson-Bey recommended looking for tests that state they’re at least 99% percent accurate.
FDA registration: As a Class I medical device, ovulation tests must adhere to FDA standards, and the packaging should state that it is FDA-registered. You can use this link to search for a brand’s name to find out if it’s FDA-registered.
Who should use an ovulation test
There are a few reasons you might want to use an at-home ovulation test.
1. You’re trying to conceive.
While this is the most common reason to use OPKs, it’s important to note that you don’t have to use ovulation predictor kits to get pregnant. Most couples who have unprotected sex without timing it to the LH surge will still become pregnant within a year, according to Dr. Jackson-Bey.
Couples who have trouble conceiving often think they should try using OPKs before seeking treatment, but that simply is not true, Dr. Jaime Knopman, MD, a board-certified reproductive endocrinologist at CCRM Fertility told Insider.
However, using an OPK is a cheap and easy way to confirm you are ovulating if you’ve been trying to a few months and haven’t had success, or if factors like work and long-distance relationships influence how often you are able to try and you need to narrow in on your window, Dr. Jackson-Bey added.
Since the tests tell you approximately when you’re going to start ovulating, you can then time intercourse appropriately for max chances of conception. “Essentially, the egg can only be fertilized for about 24 hours after ovulation, so ideally you want the sperm there first, so that it’s just waiting for the egg to be fertilized,” Dr. Jackson-Bey explained. (Fun fact: Sperm can live in the cervical mucus or the upper genital tract for three to five days.)
2. You want to avoid getting pregnant.
This isn’t the most common use for OPKs, but just as it can help you narrow down the days to have unprotected intercourse to get pregnant, it can also help you determine which days you absolutely shouldn’t have unprotected sex if you don’t want to get pregnant. Most often, people who are using the fertility awareness method to avoid pregnancy are the people incorporating LH tests into their family planning efforts.
3. You’re looking to identify menstrual cycle issues.
For those with irregular periods or who have been trying to conceive without luck, ovulation predictor kits might provide some insight into what’s going on with their menstrual cycle. “Women with polycystic ovary syndrome (PCOS) can actually have a higher baseline LH, which means that they’re always going to show positives,” Dr. Jackson-Bey explained. In this case, a positive result doesn’t necessarily mean you’re ovulating. On the other hand, women who don’t ovulate at all may never get a positive result.
“One thing I always tell patients is you should see a negative followed by a positive,” Dr. Jackson-Bey said. In other words, if you’re testing every day during the time frame between periods and you don’t ever get a positive result followed by a negative result, it’s time to head to your doctor to see what’s going on. (Learn more in our FAQs.)
4. You’re just curious to learn more about your cycle.
OPKS might also be helpful if you just want to see whether or not you’re ovulating. “There’s no harm in it, it’s very low risk,” Dr. Jackson-Bey said.
She advises starting by tracking your menses and see how long your cycles are. Sometimes, people are surprised to learn that they have a shorter or longer cycle (anything between 24 and 38 days is normal, according to clinical guidelines). Jackson-Bey added it’s helpful to have this basic information first. Then, if you wanted to add in OPKs to see when you’re ovulating and see if it’s consistent from month to month, that might be something that’s helpful in learning more about your cycle, she said.
Are expensive OPKs always better?
“The basic versions absolutely work,” Dr. Jackson-Bey said. “You can buy [reliable] LH kits and pregnancy tests from the dollar store.” At the same time, she thinks there’s a role for some of the more sophisticated OPKs, especially if you’re finding the results difficult to interpret.
What days of your cycle should you use OPKs?
You don’t need to use OPKS for your entire menstrual cycle. Instead, most test kits come with a guide stating what day to start testing based on your usual menstrual cycle length.
For example, Clearblue recommends that people who have a 25-day cycle start using their tests on day 7, and those with a 36-day cycle start testing on day 19. After getting a positive result followed by a negative result, you can stop testing since you won’t ovulate again until after you’ve gotten your period.
How do you use an at-home ovulation test?
Because every kit is different, always use the manufacturer’s instructions as a guide, Dr. Jackson-Bey said. But typically, you want to use the test with your first morning urine. If you can’t, then you want to test around the same time each day, she added. Also make sure you haven’t had a ton of water (or liquid period) before testing, as you want minimally-diluted urine for the most accurate results.
Depending on the type of test, you’ll either hold it in the stream of your urine until the tip is saturated, or dip the tip into a container of collected urine. Afterwards, you can hold it with the tip pointing downward, or lay the test flat. “The instructions will also give you a time period of how long to use to allow it to dry, usually about a three-minute or five-minute window,” Dr. Jackson-Bey said.
It’s important to read the results within the time window specified.
Do you have to use OPK to get pregnant?
No — there are several other ways to estimate your most fertile days, including basic cycle tracking, basal body temperature, and cervical mucus. In fact, most couples will become pregnant within a year just by having unprotected sex, without any LH monitoring, Dr. Jackson-Bey said.
What should you do if you’re using OPKs and not getting pregnant?
“If you know you’re ovulating, and you’re having intercourse appropriately, but you’re not getting pregnant, say within six months, I would definitely reach out to your provider, regardless of how old you are.” Dr. Jackson-Bey said. “Similarly, if you are not getting a positive month after month, or if your results are positive pretty much every day that you use it, those situations would warrant an evaluation.”
Do OPKs confirm ovulation?
“The only way to truly confirm ovulation is with a progesterone check in the luteal phase,” Dr. Knopman says. The luteal phase is the period of time after ovulation, but before you get your period. “A progesterone level that is positive about one week after ovulation confirms ovulation. However, in people with regular menstrual cycles, positive ovulation prediction kits and predictable symptoms (like changes in cervical mucus) can be predictive signs of ovulation.”
Also, though some of the newer test kits include PdG metabolite tests, not all doctors consider them a direct substitute for the progesterone blood tests that doctors order.