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 her 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, Boh B. Reproductive endocrinology and related disorders. In: Rifai N, Chiu RWK, Young I, Burnham Carey-Ann D, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 58.

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