When to Take an Ovulation Test?

If you’re trying to get pregnant, it’s important to understand when you might be ovulating, as the “fertile window” is when you have the greatest chance of conception. 

Based on your own individual cycle, you should start taking an ovulation test 3 days before your expected ovulation day.

During reproductive ages, the ovary releases an egg every month. The process of ovulation is controlled by the hypothalamus of the brain and through the release of hormones. This means that ovulation can be impacted by hormone levels and stressors.

After the oocyte is released from the ovary, it moves into the fallopian tube. At this point, it is called an ovum or egg. The egg stays in the fallopian tube for about 24 hours, waiting for a single sperm to fertilize it.

If the egg is not fertilized by sperm during that time (and pregnancy does not occur), it disintegrates (breaks down), and menstruation (your menstrual period) begins 11-16 days later.

Ovulation tests can be a useful tool for those trying to conceive and wishing to identify the best time to try to get pregnant.

Ovulation and Pregnancy: The Fertile Window

For many, ovulating is an unnoticed process. However, for those hoping to get pregnant, knowing when you might be ovulating is important. This starts with understanding your cycle length.

Your most fertile days ("the fertile window") are the three days leading up to and including ovulation. This is when getting pregnant is most likely. So, having sex then gives you the best chance of ensuring the egg is fertilized by sperm, so you become pregnant.

But, as previously mentioned, ovulation is a delicate process. Not to mention, the woman's reproductive cycle is just one side of the equation. Sperm health is also key to your chances of getting pregnant.

As most women will attest, cycle length can be impacted by stress, exhaustion, or emotional events (like grief). Moreover, nutrition, smoking, and seasonal changes can also impact ovulation and, therefore, fertility.

When to Take Ovulation Tests

Based on your own individual cycle, you should start testing with an ovulation kit 3 days before your expected ovulation day.

Ovulation tests identify the LH surge (luteinizing hormone) 24-36 hours before ovulation. It’s important to factor in that sperm can survive in a woman’s body for up to 5 days, so if you have sex before you ovulate, there can still be sperm present to fertilize the egg.

Every woman’s cycle is different. Some of us have longer periods than others, for example. So the timing of ovulation and of taking an ovulation test is not always the same in every woman's cycle.

The most commonly referenced menstrual cycle length is 28 days (even though it is not the average menstrual cycle length). It can range between 21 to 35 days in adults and from 21 to 45 days in young teenagers. That's why most women track their own cycle with a periods calculator or diary.

The first day of a cycle is counted from the first day of your menstrual period. You ovulate about 14 days before your period starts.

So, if your average cycle is 28 days and the first day of your cycle is Day 1 of your menstrual period, day 14 in your cycle is your day of ovulation, and your most fertile days are days 12, 13, and 14. These are the days pregnancy is most likely to occur and when you should start testing with an ovulation test.

And if your average cycle is 35 days, ovulation happens around day 21, and your most fertile days are days 19, 20, and 21, and these are the days when you should take an ovulation test.

What Time of Day Should You Take an Ovulation Test?

Depending on the brand of ovulation test strips you’re using, there will be recommendations about how and when to administer the test (and how to read the results). Read these instructions closely before you start taking the tests.

In general, it’s recommended to do the urine test in the morning but not during the first-morning urine. Wait until your second time urinating (and ideally, don’t urinate for about 4 hours before.) Also: don’t drink a lot of water before the test, as this may dilute it.

Some manufacturers of ovulation test strips recommend doing the tests twice a day or even testing multiple times per day. But, again, the specific brand instructions are the ones to follow. Most brands will also have FAQs and even support on their website.

Using a Test Kit: What If Your Menstrual Cycle is Irregular?

If your menstrual cycle is irregular, being able to predict ovulation becomes much more difficult. And it is, therefore, more difficult. To understand when to use those ovulation test kits. Even with a regular cycle, the day of ovulation can move around.

Irregular cycles make it challenging to narrow the right day to use an Ovulation Predictor Kit (or Ovulation Predictor Test) and can add expense to the process. 

If you keep a period diary, it’s worth going by your shortest cycle in the last 6 months as an indication of when you’re likely to ovulate on your current cycle. It’s notable that even on an irregular cycle, the luteal phase is fairly stable and lasts about 14 days. Learn more about the phases of your menstrual cycle here.

You can also look out for the other symptoms of menopause (see the last section), especially a change in your cervical mucus. According to the American Pregnancy Association, “it is best to wait until you start to notice a build-up of fertile-quality cervical mucus before you begin testing.”

It is best to read the instructions and information on your ovulation test closely and follow individual brand instructions.

Are Ovulation Tests Accurate?

Ovulation testing strips are used to detect the levels of luteinizing hormone (LH) that are excreted in the urine. The goal is to identify the LH surge that typically happens 24–36 hours prior to ovulation. 

False-positive test results can occur in about 7% of cycles. It’s also important to factor in that since sperm can survive in a woman’s body for up to 5 days, if you have sex daily or every other day for five days prior to ovulation, this can increase the chances that sperm will be present when ovulation occurs.

There are a few other reasons your body might indicate an LH surge (luteinizing hormone) that is not accompanied by your ovulating. These include:

• Luteinized Unruptured Follicle Syndrome (LUFS): This is a surge in LH (luteinizing hormone) without the release of an egg.
• Polycystic Ovarian Syndrome (PCOS): According to the Mayo Clinic, “women with PCOS may have infrequent or prolonged menstrual periods or excess male hormone (androgen) levels. The ovaries may develop numerous small collections of fluid (follicles) and fail to regularly release eggs.”
• Pregnancy: If you're already pregnant, you may register a positive ovulation test but not necessarily be ovulating. If you suspect you're pregnant, take a pregnancy test.

Optimal fertility can vary significantly, even with predictable menstrual cycles. Monitoring menstruation and tracking changes in cervical mucus, libido, pain, or mood can be a helpful way to predict ovulation about 50% of the time.

Positive Ovulation Test? Understanding Ovulation Test Results

Most ovulation home tests are usually very straightforward (not dissimilar to pregnancy tests.) That said, take a moment to read the instructions all the way through before you sit down to pee.

Usually, you pee on a stick or strip (for some brands, you pee in a cap and insert the test stick or ovulation test strip into the cup. There will be a set waiting time, and then an indicator will appear.

Generally (again, defer to the product directions), a test line will appear. The darker the line, the greater an indication that you’re about to ovulate, i.e., dark line = positive result in detecting a surge in LH levels.

Remember: An ovulation home test doesn’t actually detect ovulation; it detects levels of LH (luteinizing hormone), which surges when you ovulate. Indeed, you might think of them as LH tests rather than ovulation tests. However, there are always low levels of luteinizing hormone in your body, so a faint line can appear at any time. This does not usually mean you’re ovulating; you want a dark line.

Using an ovulation test stick with a digital ovulation test readout can help you better interpret the results and detect ovulation more accurately.

Predicting Ovulation: Other Ovulation Signs & Symptoms

Ovulation usually goes unnoticed in many, but there are some ovulation symptoms that most women can learn to track or pay attention to understand when to take an ovulation test:

Your Basal Body Temperature Falls

One of the most objective ovulation symptoms is that your basal body temperature drops a little bit just before ovulation. Approximately 24 hours after ovulation, your basal body temperature rises and stays up for several days. If you're trying to get pregnant, it's advisable to take your temperature regularly around the time of suspected ovulation to understand when it is occurring.

Basal body temperature averages between:

• 97°F (36.1°C) and 97.5°F (36.4°C) before ovulation 
• 97.6°F (36.4°C) and 98.6°F (37°C) after ovulation 

Discharge Changes When You Ovulate

The changes in your cervical mucus over the course of your cycle also hold clues about when you might be ovulating.

If your cervical mucus is:

• Dry, damp, absent, or sticky: It’s unlikely you’re ovulating
• Clear and slippery: The probability of ovulation and, thus, conception is highest 

Your Cervix Softens and Opens Up

As you approach your most fertile time, your cervix softens. This is sometimes known as having a short, high, open, and wet cervix (SHOW). 

You May Experience Slight Twinge or Cramping

Mittelschmerz translates literally as “middle pain” and is the name for the slight twinge or cramp that some women experience when the follicle releases the egg on the day of ovulation during their menstrual cycle.

Some Light Spotting May Occur When You Ovulate

When the ovaries release the egg, a tiny follicle ruptures to allow the egg to be released. This can be a cause of spotting for a day or so.

Increased Libido or Sex Drive

A common sign of ovulation is an increased sex drive. 

Conclusion: Ovulation Predictor Kits Are a Useful Tool

Ovulation tests (aka ovulation predictor kits) are a useful tool for women hoping to get pregnant. However, it’s also worth tracking other signs and symptoms of your menstrual cycle and understanding each stage. 

If you are trying to conceive, having a holistic understanding of your entire cycle and using ovulation tests will help you zero in on the best time to take the test and increase your chances of becoming pregnant.

If you think you might be pregnant, take a pregnancy test.

Written by Jane Flanagan — Updated on January 10, 2023.

We hope you found this post informative — but remember: we’re not doctors and this post is not medical advice! While all posts are fact-checked and well researched, we always recommend you chat with your doctor about any questions or concerns you might have regarding a medical condition. We’re here to support and educate, but never with the aim of disregarding professional medical advice you’ve been given. Phew, now that that’s out of the way, you can go on living unapologetically free.