How to Use an Ovulation Test

Reviewed by Dan Brennan, MD on February 22, 2021

An ovulation test — also called an ovulation predictor test, OPK, or ovulation kit — is a home test that checks your urine to let you when you’re most likely to be fertile. When you get ready to ovulate — release an egg for fertilization — your body produces more luteinizing hormone (LH). These tests check the levels of this hormone. 

By detecting a surge in LH, it helps predict when you will ovulate. Knowing this information helps you and your partner time sex for pregnancy.

Where to Get an Ovulation Test 

You can buy ovulation tests at most drugstores. These kits usually come with test sticks or paper strips. You can also buy a digital ovulation test that connects a test stick into a digital reader.   

When to Take an Ovulation Predictor Test

For women with average 28- to 32-day menstrual cycles, ovulation usually happens between days 11 and 21. You’re most likely to become pregnant if you have sex three days before ovulation. 

If your typical menstrual cycle is 28-days, you would perform an ovulation test 10 or 14 days after starting your period. If your cycle is a different length or irregular, talk to your doctor about when you should take a test.  

You can take an ovulation test at any time of day. But the morning may give you the best results. To boost your chance of an accurate reading, don’t drink a lot of fluids in the four hours before a test. This helps make sure your urine and LH levels are concentrated.

How to Take an Ovulation Test

Read the instructions in your ovulation predictor kit. Not all tests work the same way. Typically, you’ll follow these steps:

1.Unwrap a test stick and remove the cap from the absorbent tip. 

2.Insert the test stick into the test holder and listen for it to click in place. The test ready symbol will appear on the test holder.

3.Place the absorbent tip of the test stick in your urine stream for 5 to 7 seconds. You can also collect a sample of your urine in a clean, dry container and dip the absorbent tip of the test stick into the sample for 15 seconds.

4.Leave the absorbent tip pointing down for about 20 to 40 seconds until the test ready symbol begins flashing. Replace the cap on the test stick and wipe off any excess urine.

5.Within 3 minutes you should get a test ready symbol. The display will show either an empty circle, indicating a negative result, or a smiley face, indicating a positive result. If the test ready symbol doesn’t start flashing, the test didn’t work and an error symbol will appear on the display within 10 minutes. You’ll need to take the test again using a new test stick.

6.Press the “Eject” button to remove the test stick. Wipe the test holder clean and wait until the display clears before inserting a new test stick.

How Ovulation Predictor Kits Can Help With Pregnancy

If your ovulation test gives a positive result, it sensed a surge in LH in your urine. That means ovulation should begin within a day or two. Couples planning to become pregnant should have sex within the three days following a positive test. This boosts the chances of an egg becoming fertilized once it’s released from the ovaries.

Advantages and Disadvantages of Using an Ovulation Test

Ovulation predictor kits help couples plan for pregnancies but come with pros and cons. Advantages of using an ovulation predictor kit include:

  • Ease of use. Ovulation predictor tests are easy to use and work much like home pregnancy tests. Each kit includes several test sticks or strips, which let you test multiple times.
  • Effective detection. Ovulation tests are 97% accurate in detecting an LH surge, making them highly effective at predicting ovulation. 
  • Availability. Ovulation tests can be bought at drugstores and pharmacies and don’t require prescriptions.
  • Convenience. Other ovulation detection methods require you to be committed every day. Ovulation predictor tests can be conducted more quickly and conveniently.

Disadvantages include:

  • Limited detection. Ovulation tests detect LH levels, but they don’t give you an exact date of ovulation. Eggs may not emerge even after an LH surge.
  • Problems testing women over 40. Women over 40 and women near menopause have high LH levels. This makes it less likely an ovulation predictor kit can give accurate results for this age group.
  • Issues with fertility drugs. Women using fertility drugs such as the hormone human chorionic gonadotropin (hCG) may cause ovulation tests to deliver inaccurate results.
  • High price. Ovulation test kits are expensive, and you may want to test repeatedly. That can add up. 

Show Sources


Apollo Fertility: “Pros and cons of ovulation predictor kits.”

Frontiers in Public Health: "Urinary Luteinizing Hormone Tests: Which Concentration Threshold Best Predicts Ovulation?"

Mayo Clinic: "How to get pregnant."

Office on Women’s Health: “What happens during the typical 28-day menstrual cycle?”

UNC School of Medicine: “Ovulation Predictor Test Instructions."

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