When women are struggling to conceive, several methods can help to detect the cause of the problem. First, it is important to know, through ovulation tests, whether she can ovulate or not. Indeed, the reproduction process begins with ovulation, i.e., the release of an egg (by one of the ovaries) that will be fertilized by a sperm (male gamete). Besides, ovulation-related problems are the most common causes of infertility in women. (1)

Apart from any fertility problem, a woman who wants to conceive may use ovulation tests to determine the best time to have sex that could lead to pregnancy. These tests can also be used by women who want to track their ovulation to avoid getting pregnant. In-depth knowledge of how these tests work is, therefore, useful.

This article will review the essential points you want to know about ovulation tests.

What is an ovulation test, and what does it tell you?

The ovulation test shows a woman’s fertile days. The period that a woman is fertile in a menstrual cycle is known as the fertile window. It is the time in the cycle when she has the best chance to get pregnant.  It begins five days before ovulation and lasts until the day of ovulation. Once the egg is released, it can survive only for 12 hours to 24 hours, while the sperm can survive five days in the genital tract. The fertile window is key to get pregnant or avoid pregnancy. It helps you set time for successful conception or lets you know when you need backup birth control.
The ovulation test detects the presence of Luteinizing Hormone (LH) in the urine. Indeed, ovulation results from the hormonal spike of LH, which occurs 28 to 36 hours before ovulation. Practically, when the LH level is high in the urine, this means that ovulation will occur within two days.

What are the different types of ovulation tests?

An ovulation can be detected through a blood test or urine. Urine tests, which are the main focus of this article, work like pregnancy tests. It is usually a strip or a cassette on which the urine is soaked. There are also digital ovulation tests that have the advantage of eliminating the risk of misreading the result. The criteria for concluding that a result is positive is generally indicated on the instructions of the kit.

There are two principal types of ovulation test:

  • standard ovulation tests_ This type of test only detects LH hormone
  • advanced ovulation tests_ These tests detect the presence of two hormones. There is estradiol in addition to LH hormone. Estradiol levels increase many days before LH, which gives a more advanced warning of ovulation.

How accurate are ovulation tests?

Ovulation tests are found over the counter and can be used at home. These tests are not as accurate as blood tests, but they give a good estimation of the fertile window. Ovulation tests are approximately 98 to 99% accurate.

When is the best time during your cycle to start taking an ovulation test?

First, you need to know the length of your normal menstrual cycle. It can be anywhere from 20 to 45 days long.

  • When you have a regular cycle of 28 days, some doctors recommend taking the test around the 10th day after the beginning of your periods.
  • When the cycle is one day shorter (27 days) or one day longer (29 days), you remove or add one day to the 10 days. It means that you begin the ovulation test on the 9th day for 27 days cycle or the 11th day for 29 days cycle.
  • For irregular and longer periods, unfortunately, you will need to do more testing every month. You can start a few days after the beginning of your periods and then three-time a week.

What time of the day can you take an ovulation test?

You can take your ovulation test at any time of the day. But you should test at approximately the same time each day. Drinking a lot of water or any fluids can dilute the LH in your urine. Therefore, it’s best to reduce the amount of liquid you drink two to four hours before testing. You can also use the first urine in the morning.

What to do when no ovulation is detected?

When no ovulation is detected after a month of testing, it may mean that you started testing too late into your cycle. You should start testing two or three days earlier, the next cycle, and take the test daily. This can be costly, but it will give you the best chances to effectively detect the peak of LH hormone.

After three cycles of testing without any LH surge detection, you should go to your doctor to run some blood tests to detect the ovulation accurately.

How long after the ovulation test can you take a pregnancy test?

The implantation usually occurs about nine days after the fertilization of an egg. But sometimes, it may occur as early as six days or as late as 12 days after fertilization. It should be noted that the secretion of the pregnancy hormone  HCG (Human  Chorionic  Gonadotropin) occurs only after the implantation of the egg. Blood detection of HCG is possible 3 to 4 days after implantation. Therefore, you can do a pregnancy test two weeks after a positive ovulation test or a week after your period is due to avoid false-negative results.

Key Points

  • Ovulation tests are essential tools for any woman wanting to get pregnant.
  • They are easy to use and accessible.
  • They detect the period of ovulation and fertility in women by highlighting the LH surge.
  • A surge of LH in the urine predicts that the ovulation process will occur within 24 to 48 hours.
  • The fertility window lasts, on average, five days.
  • It is recommended to take the ovulation 10 days after the first day of menstruation for a regular 28-day cycle.
  • Taking the test at the same time every day and reducing the amount of liquid you drink before the test help achieve optimum results.
  • It is best to wait at least two weeks after a positive ovulation test to do a pregnancy test.


  1. https://www.womenshealth.gov/a-z-topics/infertility
  2. https://www.who.int/reproductivehealth/topics/infertility/burden/en/
  3. Julien J. Stirnemann, Adeline Samson, Jean-Pierre Bernard, Jean-Christophe Thalabard, Day-specific probabilities of design in fertile cycles resulting in spontaneous pregnancies, Human Reproduction, Volume 28, Issue 4, April 2013, Pages 1110-1116, https://doi.org/10.1093/humrep/des449
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About the Author

Hermione M.

My name is Hermione. I am the founder of WomenH and I write about women's health, wellness, mental health, and personal growth. I created this platform to inspire women to take care of themselves mentally, physically, and emotionally to become their best selves. Thank you for stopping by.

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