When to start taking an ovulation test

An ovulation home test is used by women. It helps determine the time in the menstrual cycle when getting pregnant is most likely.

The test detects a rise in luteinizing hormone (LH) in the urine. A rise in this hormone signals the ovary to release the egg. This at-home test is often used by women to help predict when an egg release is likely. This is when pregnancy is most likely to occur. These kits can be bought at most drug stores.

LH urine tests are not the same as at home fertility monitors. Fertility monitors are digital handheld devices. They predict ovulation based on electrolyte levels in saliva, LH levels in urine, or your basal body temperature. These devices can store ovulation information for several menstrual cycles.

Ovulation prediction test kits most often come with five to seven sticks. You may need to test for several days to detect a surge in LH.

The specific time of month that you start testing depends on the length of your menstrual cycle. For example, if your normal cycle is 28 days, you'll need to begin testing on day 11 (That is, the 11th day after you started your period.). If you have a different cycle interval than 28 days, talk to your health care provider about the timing of the test. In general, you should begin testing 3 to 5 days prior to the expected date of ovulation.

You will need to urinate on the test stick, or place the stick into urine that has been collected into a sterile container. The test stick will turn a certain color or display a positive sign if a surge is detected.

A positive result means you should ovulate in the next 24 to 36 hours, but this may not be the case for all women. The booklet that is included in the kit will tell you how to read the results.

You may miss your surge if you miss a day of testing. You may also not be able to detect a surge if you have an irregular menstrual cycle.

DO NOT drink large amounts of fluids before using the test.

Drugs that can decrease LH levels include estrogens, progesterone, and testosterone. Estrogens and progesterone may be found in birth control pills and hormone replacement therapy.

The drug clomiphene citrate (Clomid) can increase LH levels. This drug is used to help trigger ovulation.

The test involves normal urination. There is no pain or discomfort.

This test is most often done to determine when a woman will ovulate to assist in difficulty in getting pregnant. For women with a 28-day menstrual cycle, this release normally occurs between days 11 and 14.

If you have an irregular menstrual cycle, the kit can help you tell when you are ovulating.

The ovulation home test may also be used to help you adjust doses of certain medicines such as infertility drugs.

A positive result indicates an "LH surge." This is a sign that ovulation may soon occur.

Rarely, false positive results can occur. This means the test kit may falsely predict ovulation.

Talk to your provider if you are unable to detect a surge or do not become pregnant after using the kit for several months. You may need to see an infertility specialist.

Luteinizing hormone urine test (home test); Ovulation prediction test; Ovulation predictor kit; Urinary LH immunoassays; At-home ovulation prediction test; LH urine test

Jeelani R, Bluth MH. Reproductive function and pregnancy. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed.: Elsevier; 2022:chap 26.

Nerenz RD, Jungheim E, Gronowski AM. Reproductive endocrinology and related disorders. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. St Louis, MO: Elsevier; 2018:chap 68.

Updated by: John D. Jacobson, MD, Department of Obstetrics and Gynecology, Loma Linda University School of Medicine, Loma Linda, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

Let's talk about ovulation, when and how to use an ovulation test, and what the results mean. 

When should you start testing for ovulation? The process may sound like they’d require at least three professionals in gloves, those horrible stirrups, and some discomfort. Happily, though, this is one part of the pregnancy process that’s easy to self-administer, and we’ll tell you how, when, and why.

Backing up—remember, ovulation is when your ovaries release an egg, which travels down your fallopian tubes, where it waits for sperm to come and fertilize it (not the most feminist narrative, but here we are). The Natalist Ovulation Test Kits let you know when you’re going to ovulate, so that you can make sure there it gets a welcoming (or fertilizing) committee. 

Right before ovulation is the time to have lots of sex to optimize your chances of getting pregnant. Ovulation predictor tests help you find that peak fertility time.

What’s an ovulation test?

Simply put, an ovulation test is a test that lets you predict when you are going to ovulate. This is important because eggs only live for a short time after they are released—24 hours max. If you’re trying to get pregnant, you want to make sure you have intercourse before you ovulate to optimize your chances of getting pregnant. Sperm are relatively hearty and can survive for 5-6 days inside the female reproductive tract so if you have sex before ovulation, they’ll stick around waiting for their moment to act.

There are many different types of ovulation tests—tests that you pee on directly, tests that are dipped into a cup of urine, tests that are digital—but they work by the same basic mechanism: by detecting Luteinizing Hormone (LH) in your urine, which your brain makes to tell your ovaries it’s time to release an egg. LH levels surge about 24-48 hours before ovulation—conveniently when you're most likely to get pregnant. 

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We make easy-to-use, plastic neutral ovulation tests in the form of midstream tests and test strips, so you can choose what feels right for you. And they cost less than what you’ll find at the drugstore. 

When should you start testing for ovulation?

When you start tracking ovulation, you’ll need to know where you are in your menstrual cycle to figure out when to start testing. There are subtle changes in the body that you can use to detect ovulation, such as cervical mucus or basal body temperature changes to determine your most fertile day. You can also figure out your cycle length exactly by counting the day your period starts (the first day of full menstrual flow) as day one, and continue counting until the day before your next period starts. The total number of days is your cycle length. For most women, this is around 28 days. If your cycle length varies each month by more than three days, choose the shortest cycle you’ve had in the last six months.

To find an exact date to start testing you can either:

• Start testing daily around day 10 to make sure you catch your ovulation, in case you ovulate earlier or later than day 14. If you use our Ovulation Test Kit, it even comes with an ovulation tracker to track results.
• Or, you can use the table below to figure out which day of your cycle to start testing. 

You’ll want to test for a few days in a row to find your usual LH surge timing. Some women have irregular cycles or ovulate on different days of their cycle each month. Everyone is different— luckily, ovulation tests can help familiarize you with your own body’s variations. Our midstream boxes include seven tests, and our test strips include 30, so you have plenty of tests per cycle. 

Still have questions about ovulation, symptoms, fertility treatment, or testing? Check out Dr. Naz’s article here. 

What time of day is best to use an ovulation test kit?

You can test anytime of day, but make sure not to test after drinking a lot of fluid because it can dilute your urine. This is why many women prefer to test first thing in the morning when the urine is more concentrated.

How do I use an ovulation test?

To ensure your fertile window testing goes correctly, follow the instructions on the test. If it’s positive, you’ll ovulate in the next 12-24 hours, and, if you haven’t already, you should start having sex (i.e. the “baby dance”).  Remember, the ideal time to have sex for baby-making is five days before ovulation and the day of ovulation (AKA your fertile window)., Testing for ovulation will help you determine the pattern for your typical ovulation day so you can take full advantage of your fertile window every cycle. 

A few important things to know before testing:

• Make sure you haven’t urinated for at least two hours.
• Don’t drink a bunch of liquid in the few hours before testing. It can dilute your urine and cause a false-negative result—meaning you could be ovulating but the test will show you’re not.
• Don’t open the wrapper until you’re ready to start testing, and don’t use the ovulation test strip if the wrapper is damaged or torn.
• Don’t touch the test window.
• Don’t urinate on the test window.

Don't forget the fertility lube!

Sperm-friendly lubricants (also known as fertility friendly or TTC lube) are great for couples trying to conceive. Not only do lubricants help reduce friction and make sex more pleasurable, but the right lubricant can make sure that nothing is in the way of sperm meeting egg.

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If I'm pregnant, will my ovulation test be positive?

You might’ve read online about women using ovulation tests to test for pregnancy. Ovulation tests detect LH, which is similar to the chemical that pregnancy tests look for, human Chorionic Gonadotropin (hGC). In fact, they bind to the same receptor.  If you’re pregnant, you might get a faintly positive ovulation test that’s actually detecting hCG, not LH. This is more likely to be true the further along you are in pregnancy since your levels of hCG in urine will be higher.

Bottom line: use the ovulation tests to predict ovulation and pregnancy tests to detect pregnancy for better accuracy. To make this easier for you, we offer a test pack so you can find your fertile window, and test for pregnancy shortly after. 

Can I Use An Ovulation Test If I Have An Irregular Cycle?

If your cycle length is different month to month by more than three days, choose the shortest cycle you’ve had in the last six months to figure out when to start testing. Another option is to start testing the day after the last day of your period in order to guarantee that you do not miss your LH surge.

How accurate are ovulation tests?

When they’re used correctly, ovulation tests are up to 99% effective in detecting LH surges and finding the ideal time to try to conceive. 

There are special cases where ovulation tests may not be the best choice for finding your fertile window. If you have polycystic ovary syndrome (PCOS), primary ovarian insufficiency, or other medical conditions where LH, you are more likely to get a false-positive result, which is when the test falsely detects an LH surge when one is not present. Some women with irregular periods don’t ovulate each cycle, so they won’t see an LH surge in those months.  It can take up to 3 months to figure out your own cycle patterns, especially if your cycle is irregular, so hang in there. If you have questions, we urge you to reach out to us.  If you’re concerned about your results, talk to your doctor.