Are Ovulation Test Strips Accurate?

As simple as it may sound, it is not always easy to plan a pregnancy. Women have to be in their fertile period to increase their chances of pregnancy. However, couples who are always on the go may prefer to have intercourse when it is convenient and just take a chance at conceiving.

When couples are desperate to have a baby as soon as possible, their options could be: (A) Have intercourse every day for a month or (B) Try alternative measures by using an ovulation test kit to know the best time to have intercourse and, consequently, improve their chances of conceiving.

Though option A is quite preferable, it is not always possible because people have everyday responsibilities such as work, (travel, night duty, etc).

Option B is preferred by many couples. It’s an efficient time-saving procreating method that can help women prepare physically and emotionally.

Because ovulation test strips provide efficient results, the demand for these products is growing and so is their supply. There are several ovulation test brands on the market and almost all of them promise nearly 100% accuracy. But the question that most couples ask themselves is, “Are ovulation test strips accurate?”

Getting to Know Ovulation Test Strips

An ovulation test strip is a narrow paper-thin band used for testing the presence of ovulation hormone levels in urine. The strips are long or short, depending on the brand.

The long strips can be placed directly under your urine strip, but if you have shorter strips, you might want to urinate in a cup and slowly dip the strip.

Because some brands do not recommend urinating directly on the test strip, it is always advisable to read the manufacturer’s instructions before using the kit.

Ovulation test strips are commonly called ovulation predictor kits (OPK). They work like a pregnancy test but instead of detecting pregnancy, an ovulation test strip will determine whether you will ovulate soon.

While most ovulation tests are sold as strips, digital tests are also available. Strips will show lines while digital ovulation tests will show a YES+ or a NO-. You can use either strips or a digital device depending on your preferences. However, the bottom line is that what matters is the accuracy of the test.

Are Ovulation Test Strips Accurate?

Couple Planning Family with Ovulation Test and Calendar

Your body secretes luteinizing hormone (LH) and estrogen when you are approaching ovulation. Ovulation tests, either standard strips or digital tests, detect the presence of LH (and estrogen in the case of advanced digital ovulation tests) in your urine.

Most ovulation test devices have gone through extreme quality checks by manufacturers and government agencies. Some devices are approved by the Food and Drug Administration (FDA) and thus guarantee accurate results. So, yes, ovulation test strips are accurate.

Although the devices are guaranteed to give accurate results, there are several factors that may affect their accuracy.


Your health can affect the accuracy of the ovulation test results. For example, women with polycystic ovarian syndrome (PCOS) typically have disorders of hormone balance and often face difficulties in getting pregnant.

In these women, while ovulation test strips can detect LH levels accurately, there is no guarantee that ovulation will occur. Some practitioners recommend that women with PCOS use devices such as Ovacue, which does not predict ovulation based on the attainment of a pre-determined level of a given hormone (either LH, estrogen, or both).


Most women believe it is best to test with first morning urine. However, you might miss your LH surge since the hormone might not have reached levels to be detected by an ovulation test strip.

While it is thought that the LH surge occurs in the early hours of the morning, sufficient levels might not be present in the early morning urine.

To achieve a more accurate result, it is best to use an ovulation strip at any time of the day except in the morning. But test times might vary depending on the type of ovulation test and brand.

This post gives more detailed instructions on the use of standard, digital, and advanced digital OPKs.

Medication and Contraceptives

Women who are under medication that contain human chorionic gonadotropin (usually in infertility treatments) may get inaccurate results.

Women who also use a hormonal contraceptive (or those who recently stopped using hormonal birth control) must consult their physicians first, as the use of ovulation tests may give misleading results.

What is the Sensitivity of At-Home Ovulation Predictor Tests?

A study published in Frontiers in Public Health examined the first morning urine of 107 women for hormonal assessment and performed serial ovarian ultrasound scans on these women for signs of ovulation.

The investigators found that the best time to predict ovulation was within 24 hours after the first positive test. Women were more likely to get a false positive result in the following scenarios:

  • Their urine was tested further in their cycles
  • Two or three consecutive tests were performed
  • Ovulation had been predicted within the last 48 or 72 hours.

They determined that the ideal threshold to predict ovulation varied from 25–30 mIU/mL and suggested that manufacturers of at-home ovulation tests should disclose their tests’ threshold to potential users.

What is the Sensitivity of Your Favorite Ovulation Test Brands?

Most manufacturers report that their ovulation test strips have a sensitivity of 25 mIU or 25 ng/L. These include the following: 

How Do I Get Accurate Results?

Here are a few quick tips you that you can follow to help you obtain accurate results:

  • Take the test in the middle of the afternoon or in the evening. Do not perform the test early in the morning.
  • Do the test every day at the same time.
  • Test twice a day. Performing the test twice will give you a more comprehensive result. However, this may prove to be expensive. You can buy cheap ovulation test strips in bulk from online stores or your local drugstore.
  • Avoid drinks that contain caffeine, as they have a diuretic effect and will cause you to urinate more often. It is important that you collect your urine a few hours after holding your urine, which would be impossible to do if you drink coffee or other caffeinated beverages. In general, when taking an ovulation test, it is recommended that you do not drink a lot of liquids; this is to avoid the dilution of urine and consequently, decrease the detection of LH in your urine.

Common Mistakes to Avoid When Using an Ovulation Test

If you’re waiting for a positive ovulation test to have intercourse, think again. Ovulation predictor tests were designed to warn you that you’re going to ovulate soon.

The downside with these tests is that don’t tell you when exactly you’re going to ovulate. Will it happen in one hour? Eight hours? Twelve hours or longer?

A positive ovulation test only tells you that you’re currently in your LH surge. There’s no way for you to tell when your surge began. Thus, you can even get a positive result after ovulation if your LH surge is on the longer side. Conversely, you might have a hard time catching your surge on an ovulation test if it is on the short side.

The bottom line is that you do not need to wait for a positive LH test to ‘baby dance’ because, by the time you get a positive result, you may have already missed some of your most fertile days. It is preferable to start having intercourse when the test line starts getting as dark as the control line. Also, watch out for other fertility signs such as fertile cervical mucus.

Another mistake to avoid is having sex the day after you ovulate. To maximize your chances of conceiving, you should have sex during the two to three days leading up to, and including, ovulation. If you have sex during any of these days, your chances of conceiving range between 20 and 30 percent

I Don’t Like Using Ovulation Test Strips, What Are the Alternatives?

You can opt for other alternative methods such as using a basal thermometer or monitoring ovulation (calendar method).

A basal thermometer will let you know if ovulation has occurred. If you do not know how to use a basal thermometer to determine your ovulation days, this post explains how to do it

By constantly monitoring your everyday temperature, you will notice a temperature shift during your cycles. It does take a bit of practice to understand your fertility patterns, but you’ll eventually get a hang of it after a few cycles. 

In the calendar method, you should count the days of your menstrual cycle. This could be challenging if you have irregular cycles.

You would know if you’re ovulating when you’re halfway through your cycle and feel pain in the lower abdomen. This method is effective but does not always guarantee that ovulation has occurred.

Another device that makes ovulation tracking easier is the Ava bracelet. This bracelet tracks nine physiological parameters and predicts your most fertile period.

Other high-tech fertility monitors that have been proven to be efficient include Bellabeat Leaf, Lady-Comp, Ovacue, and ClearBlue monitor.


You will probably get the best results with an ovulation test if you follow the instructions of the manufacturer. If you’ve been testing for quite some time, you might find it difficult to keep your cool.

Some women have difficulties in getting pregnant due to an underlying medical condition. It is always advisable to consult a health expert if you’ve been trying for more than six months (if you’re above 35 years) and more than 12 months if you’re younger.


I’m Princila, founder of Check Ovulation and a proud mom of two. I’m an alumna of James Lind Institute. After working in clinical jobs, my passion for writing took its toll, and I ended up switching careers to work in the medical publishing industry. I also have a passion for healthy food, which prompted me to take several online courses in nutrition and health offered by Wageningen University. (I still haven’t completed the courses thanks to my busy mommy schedule!). When I’m not writing/editing scientific and medical manuscripts or taking care of my family, I use my free time to research, learn, and write about healthy living. I have also authored a few books in the self-help niche using the pen names Princila Murrell or PN Murray. Protection Status