5 Best Ovulation Tests to Figure Out When You’re Fertile

Want to take some of the guesswork out of trying to get pregnant? Track your hormone surges to get a better sense of when you’re ovulating with one of these ovulation predictor kits.
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July 16, 2021
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So you’re eager to get pregnant? Knowledge is power, and one way to up the ante on your efforts (you know, besides getting busy!) is with a little bit of early education and some solid data. That means charting your cycle and predicting your most fertile days. Of course, if counting is not your strong suit, you could also try using an ovulation predictor kit. These helpful ovulation tests can take the guesswork out of figuring out when you should get down to business (and you thought math wasn’t sexy!).

Whether you’re trying to get a handle on when you actually ovulate or taking the next steps in figuring out why you haven’t successfully conceived yet, an ovulation test can be a nifty tool. Of course, while the science of an ovulation kit is advanced, the reality is that not all women experience ovulation like clockwork—and this can make testing both useful and challenging. Want to learn how an ovulation test works, when to take one and what to do when you read the results? We’re sharing everything you should know—plus revealing the best ovulation test options for your needs.

What Is an Ovulation Test?

If you’re trying to figure out when to have sex to potentially conceive, an ovulation test can help. How? Before we explain, let’s take a virtual trip back to middle school and recap sex-ed class, shall we? Ovulation is the once-a-month release of an egg from your ovary; it travels down the fallopian tube and is available for fertilization. According to the American Pregnancy Association, the average cycle is between 28 and 32 days. Ovulation typically occurs between Day 11 and Day 21 of a woman’s cycle (counting from the first day of her last period).

So back to the question: What is an ovulation test? Simply put, it’s a strip or wand you pee on to help you narrow down that timeframe and identify your peak fertility window each month. “There are simple test strips that are very similar to urine pregnancy tests, and there are digital tests that can evaluate the results electronically,” explains Shaun Williams, MD, partner and reproductive endocrinologist at Reproductive Medicine Associates of Connecticut. Regardless of whether you go low-budget or tech-savvy, each option serves the same purpose: to help you “determine the exact day of ovulation,” says Williams.

How Do Ovulation Tests Work?

Now that you understand what it is, let’s break down how an ovulation test actually works. Ovulation predictor kits look for luteinizing hormone (LH) in your urine. LH is produced in the pituitary gland and surges each month just before ovulation, explains Williams. “These tests are usually negative until the LH surge, and positive once ovulation occurs the very next day,” he says. So just because you get a negative today doesn’t mean it won’t be positive tomorrow; you may need to take tests for a few consecutive days as you think you’re approaching ovulation. Since ovulation typically occurs 24 to 36 hours after a positive ovulation test, these predictor kits can help you time when you have sex for the greatest chance of getting pregnant.

When to Take an Ovulation Test?

Figuring out when to take an ovulation test can be tricky—mostly because not all women ovulate on a predictable 28-day calendar. To that end, having a basic idea of your cycle can help narrow it down. Tracking your menstrual cycle (check out our ovulation calendar!) can give you a leg up, as can monitoring for changes in cervical mucus, taking your basal temperature and looking for other subtle symptoms of ovulation.

“Ovulation tests are usually performed daily, within four to five days of ovulation. For women with a 28-day cycle, starting to test on Day 10 of the cycle can predict ovulation over the next five to six days. For women with more variable cycle lengths, beginning ovulation testing on Day 8 of the menstrual cycle might be helpful,” says Williams. He acknowledges that if a woman’s cycle length is very long (35+ days), it becomes increasingly challenging to understand when ovulation is occurring and determine the best day to begin testing.

Once you do start testing, you’ll want to use “early morning urine,” says Robert Kiltz, MD, an ob-gyn, reproductive endocrinologist and the founder of CNY Fertility in Syracuse, New York. This helps to ensure the highest concentration of detectable LH in your urine.

Ovulation Test Results

The most important thing to do when taking an ovulation test: read the instructions! While these kits tend to be pretty intuitive, user error is possible, so take the time to do your due diligence. Here’s what you need to know when taking a test and reading the results—plus, some important next steps.

How to read an ovulation test

You’ll pee directly on most stick tests; strip tests involve dipping into a cup of urine. Either way, results are usually available in about five minutes. A control line will always appear to indicate that the test is working; if the test line appears, there is LH in your system. The darker it is, the higher the concentration. Of course, digital tests can be more user-friendly as they give you a definitive “positive” or “negative” displayed as written text—not easy to confuse or interpret incorrectly.

A positive result means you’re experiencing a surge in LH and will be ovulating in the next 12 to 36 hours. To optimize your chances of conception, you‘ll want to have sex asap. “Intercourse should occur on the day of the positive ovulation test,” says Williams, explaining that this is because “sperm can live up to 72 hours following intercouse.” Having sex on the exact day of ovulation actually has a slightly lower rate of success, but as Willaims notes, a typical “ovulation predictor test only provides 24 hours notice before ovulation,” so you do the best you can!

The next step is the hardest: waiting to see if your efforts paid off. “Checking a home pregnancy test 12 to 14 days after ovulation should return a positive result if pregnancy has occurred,” says Williams. And if you get a negative? Well, you can start the whole process over again in about two weeks. Of course, if you have any concerns, are unable to detect a surge over the course of your cycle or are experiencing trouble conceiving, consult your doctor for next steps.

How accurate are ovulation tests?

According to Kiltz, ovulation tests are typically 95 to 98 percent accurate at detecting LH in the urine. While that’s encouraging, they’re not the best option for every woman: “The biggest issue is that many people don’t ovulate… The other part is that so many women with polycystic ovary syndrome (PCOS) happen to have higher LH levels, so they may get a false positive, thinking they’re ovulating but in fact they’re not.” Certain fertility-enhancing medications can also alter the results of an ovulation predictor. Furthermore, some “women ovulate regularly with a normal LH surge, but the LH concentration in the urine does not get detected,” says Williams—essentially rendering these ovulation kits useless.

Best Ovulation Test Options

Ready to get intimately familiar with your cycle? We’ve rounded up some of the best ovulation tests on the market—plus, their pros, cons and price points.

Image: Courtesy Clearblue

Best digital ovulation predictor kit: Clearblue Advanced digital ovulation test

How it works: This urine test looks for LH and another hormone, estrone-3-glucuronide (E3G). Clearblue says this additional hormone can help pinpoint four fertile days, while most digital tests just offer two. A flashing smiley face appears during the high fertile days leading up to ovulation and then turns to a solid smiley when you reach peak fertility. Those are your cues to schedule date night stat!

How accurate is it?: According to Clearblue, it’s over 99 percent accurate at detecting the LH surge in lab studies.

Pros: It’s especially good if you’re a planner. Instead of just a day or two advance notice of your most fertile days, this test typically gives you a four-day window.

Cons: Some users report that the tests sometimes show high fertility for up to a week, without switching to peak, particularly in the first month of use. It’s also not recommended if you have polycystic ovary syndrome (PCOS).

Price: $27 for 20 sticks,

Image: Clearblue

Best bells-and-whistles ovulation predictor kit: Clearblue fertility monitor

How it works: This handy gadget is used along with separate strips. Use a strip for a urine test and then place it in the touchscreen device to be read. The monitor will measure LH levels to identify your two peak fertile days, plus the one to five high fertile days leading up to them. It stores information from your last six cycles to customize your reading.

How accurate is it?: Clearblue says it’s been tested in a lab to detect the LH surge with over 99 percent accuracy.

Pros: It generates a personalized reading based on your past cycles and offers peak and high fertile days.

Cons: It’s pricey! And it may not work properly if you have cycles that last less than 21 days or more than 42 days.

Price: $127 for one monitor,; $55 for 30 test strips (sold separately),

Image: Courtesy Wondfo

Best budget-friendly ovulation predictor kit: Wondfo ovulation test strips

How it works: Like other urine tests, this one looks for LH. But unlike many other options, there’s no plastic wand to hold. It’s just a paper strip that looks like a litmus test (remember those from high school chemistry?). You’ll pee into a cup and then dip in the strip for three seconds. Five minutes later, it will be ready to read. If a test line that’s as dark or darker than the control line appears, you’ll ovulate within the next 24 to 48 hours.

How accurate is it?: Wondfo says their test is 99 percent accurate at detecting the LH surge. What’s more, the user reviews speak volumes, with lots of success stories in the mix.

Pros: They’re ideal if you think you’ll be testing a lot. You can’t beat the price!

Cons: Some find the results tough to read, since line darkness may be hard to judge.

Price: $15 for 50 strips,

Image: Courtesy First Response

Best ovulation predictor kit and pregnancy test combo: First Response 7-test ovulation kit and pregnancy test

How it works: Want to approach this journey with extra optimism? This two-for-one option offers you seven days worth of ovulation tests and one early-detection pregnancy test—so you can really measure your success!

How accurate is it?: First Response says their ovulation predictor kit is 99 percent accurate at reading your LH surge. Moreover, their early-result pregnancy test is more than 99 percent accurate when taken on the day of your expected period.

Pro: Preparation is key! You get a week’s worth of ovulation tests and a pregnancy test—one less purchase to make later in the month.

Cons: Some users have difficulty reading the ovulation line.

Price: $20 on

Image: Courtesy Modern Fertility

Best ovulation kit for tracking your cycle: Modern Fertility ovulation test

How it works: Want to learn more about your unique cycle? There’s an app for that. Modern Fertility offers a kit with 20 tests to measure your LH and a free downloadable app to help you project your LH curve—even if your cycle is somewhat irregular. Each day that you test, you’ll find out if your LH is tracking low, high or at peak concentration to help nail down your most fertile two-day window.

How accurate is it?: Modern Fertility says that its LH predictor kit is 99 percent accurate.

Pros: You can gather data to form a better understanding of your cycle. What’s more, you can subscribe and save, which is nifty if you plan on monitoring your ovulation for a while.

Cons: Some users say they detected a surge with competitor brands but not with these strips.

Price: 16 for $20 on

About the experts:

Robert Kiltz, MD, is an ob-gyn, reproductive endocrinologist and the founder and director of CNY Fertility in Syracuse, New York. He received his medical degree at the University of California, Davis.

Shaun Williams, MD, is a partner and reproductive endocrinologist at Reproductive Medicine Associates of Connecticut. He received his medical degree at Baylor College of Medicine in Houston, Texas.

Please note: The Bump and the materials and information it contains are not intended to, and do not constitute, medical or other health advice or diagnosis and should not be used as such. You should always consult with a qualified physician or health professional about your specific circumstances.

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