Ovulation Test Strips-FAQ

Ovulation test strips-frequently asked questions about using ovulation strips to predict ovulation

Below is a selection of the most frequently asked questions we have been asked about using ovulation test strips. 

We are here to help you use ovulation strips if you need us. If you do not see the answer to your question about using ovulation test strips below, then get in touch through the contact form below, or contact our UK based customer support team and we will answer it for you.

Ovulation test strips ALL Test

What is an ovulation test strip & how does it detect the most fertile time?

Ovulation test strips are also known as ovulation predictors, ovulation sticks and ovulation tests. An ovulation predictor gives you advance notice that you are going to ovulate by measuring a hormone in your urine called Luteinising hormone ( LH for short )

How does an ovulation test strip detect the most fertile time?

Ovulation tests strips work by detecting the LH level in a urine sample. This hormone LH is released & peaks just prior to ovulation and is the trigger to the ovary to release the egg. By identifying this peak in the levels of LH each month, also known as the LH surge, using an ovulation test strips, you can identify the most fertile time in a women’s cycle.

You can see our full range of ovulation test strips available to buy online.

How do ovulation test strips work?

Ovulation test strips work by detecting the female hormone, luteinising hormone, often abbreviated to LH. The ovulation test strip has a chemical embedded into it, which reacts with the hormone LH in your urine sample. This shows as a line on the ovulation test strip. The darker the line, the more of the hormone LH that has been detected by the ovulation test strip. The ovulation test strips will also have a control line. The control line on on ovulation test strip shows enough urine has been absorbed by the ovulation test strip, and that the ovulation test has worked properly.

What does a positive ovulation test strip look like?

what does a positive ovulation test strip look like

A positive ovulation test strip has two lines visible, one a control C line and one a test T line. The ovulation test strip is only regarded as positive when the test line is as dark or darker than the control line on the ovulation strip as shown in the ovulation test strip image above.

Does a faint line on ovulation test mean ovulation is coming?

The image below shows a series of ovulation test strips done over 5 days at the same time of day, and what the ovulation test strip results will look like as ovulation is coming. The T line on the strip ovulation test will gradually become darker until it is the same as the control line. The bottom strip shows what a strong ovulation test strip result will look like, and means that you have detected the LH surge. The image below shows the ovulation test strip progression from a negative ovulation test, to a the final test strip which is a positive ovulation test strip result, meaning ovulation is imminent.

faint line on ovulation test strip

When do I start testing with urine LH ovulation test strips?

For most urine ovulation test strips it depends on the length of your menstrual cycle. See below for full answer and how to work out the length of your cycle.

When to start ovulation testing with ovulation test strips

To know when to start using the ovulation test strips you first need to determine the length of your menstrual cycle. Your menstrual cycle length is the number of days from the first day of your period (menstrual bleeding) to the last day before your next period starts. Think back over the last few months to decide what your usual cycle length has been.

When is the best time to start to use ovulation test strips

To use ovulation test strips successfully to conceive, you need to know when to use them. Follow this simple guide below to when to use ovulation test strips.

  • Circle your usual cycle length on the WHEN TO START CHART below.
  • Select the number directly underneath.
  • Starting the first day of your last period, count ahead of the selected number of days on your calendar.
  • This is the day you should begin using the ovulation test strips.

When to start testing with ovulation test strip ovulation testing chart

Circle your usual  menstrual cycle length.

Cycle 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40
Start 06 06 07 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23
  • If your cycle length is 26 days start testing on day 9. (Where day one is the first day of your last period).
  • Note: If you are unsure about your cycle length, or your cycles are irregular, you may want to use your shortest cycle length when reading the chart.
  • If you do this, you may need to test for ovulation for more than 5 days.
  • You can buy LH home ovulation test strips and ovulation kits for ovulation testing through this website.

When’s the best time of day to take an ovulation test using an ovulation test strip?

The best time to collect a urine sample for ovulation testing using ovulation testing strips is usually early to mid-afternoon, ideally between 2 pm and 2.30pm. This is because studies have shown that the hormone that you are measuring in your urine sample LH, is at its highest levels at this time of day, in most women. If you tested your LH level in your urine first thing in the morning with an ovulation test strip, it is likely you would miss your LH surge, as the hormone is very low first thing in the morning.

Why do I need to restrict my fluid before I collect my urine sample for my LH ovulation test strip?

You will need to restrict your fluid intake for about 2 hours before you collect your urine sample for your ovulation test with an LH ovulation test strip. This is because if the urine sample is too dilute you may miss the LH surge, and therefore you would miss the 1st day of your most fertile period.

How do you use ovulation test strips step by step:

  1. To use an ovulation test strip also known as ovulation sticks you simply collect your urine sample at the correct time of day, usually early to mid-afternoon for most women.
  2. Then you dip the urine ovulation test strip into the urine sample for a few seconds and then lay it flat.
  3. You will see the urine running along the ovulation test strip, and you should see a Control or C line appear.
  4. This means that the ovulation test strip has absorbed enough urine.
  5. You then wait the required time as specified in the instructions for the brand of ovulation test that you are using, usually a few minutes, and then you look for a Test or T line to develop.
  6. To be positive the T line must be the same as, or darker than the C line.

Ovulation test strips-how to read results

Ovulation test strips are very simple and easy to use and also very affordable way to check for ovulation. An ovulation test strip screens urine for a hormone called LH or Luteinising hormone. LH increases rapidly just before ovulation, and is the hormone that triggers the release of the egg from the ovary. This hormone can be detected in your urine. The LH tests work by identifying when this hormone is above a certain level that is required to stimulate ovulation. This high level is known as the LH surge 

How long do the results take to appear on my ovulation test strip?

You can usually read the results on most ovulation test strips within about 10 minutes. Read the instructions for the ovulation strips that you have purchased, as they may vary a little from brand to brand. A positive result on your ovulation test will not disappear, but some negative results may later turn positive if left for longer than the specified time in the instructions. If this happens this is not a positive ovulation test result. It is best to discard the ovulation test strip once you have read the result so you will not be tempted to look at it again.

What does no LH surge on an ovulation test strip mean?

The first thing to say is don’t panic if you do not detect an LH surge on your ovulation test.

There are lots of possible explanations for not detecting the LH surge with an ovulation test strip:

  • LH surge may be too mild to be detected by the LH tests that you are using. It may be worth trying a lower sensitivity LH test.
  • Your urine sample may have been too diluted. Make sure you restrict your fluid intake for about 2 hours before you take the ovulation test
  • You may have tested for ovulation at the wrong time of day and missed the LH surge. The ideal time to do an ovulation test is early to mid-afternoon.
  • The ovulation test strip may not have absorbed enough urine. Make sure that the control line is visible. This shows that sufficient urine has been absorbed, for the test to run. If the control line is not showing dip the strip into the urine sample again.
  • The LH ovulation test strip that you are using may be faulty or out of date. Make sure that you buy your ovulation test strips from a reputable supplier, and that the ovulation tests are in date and have been stored correctly.
  • You may be ovulation testing at the wrong time of your cycle. For women who have irregular periods, knowing when to carry out an ovulation test can be very difficult.
  • You may not have used the ovulation test strip correctly. Make sure that you read the instructions before starting the ovulation test and always use a timer.
  • You may not be going to ovulate this month. This may just be a one-off, but if it happens repeatedly you should see your doctor, as it may mean that you are not ovulating and need further investigations.
  • You may already be pregnant. There is always a small possibility that you may already be pregnant. If your last period was different to usual, or very light it may be worth doing a pregnancy test.

Why do I ovulate late in my cycle?

The length of a women’s menstrual cycle varies from women to women. Ovulation occurs 14 days before your period. If you cycle is 28 days this means that you would ovulate around day 14. If your cycle is 30 days long you will ovulate around day 16. Ovulation occurring after day 21 of the cycle, is regarded by the medical profession as late ovulation.

There are many possible causes for late ovulation:

  • Hormones
  • Illness
  • Stress
  • General health issues
  • Over exercising
  • Weight too high or too low
  • Genetic problem
  • Ovarian problem such a polycystic ovaries

What should I do if I detect that I am ovulating late with the ovulation strips

If the late ovulation is a one-off, then is probably caused by stress either physical or psychological. However, if ovulation is late often this can make it more difficult to conceive and may need further investigations. Talk to your doctor if you are experiencing late ovulation or erratic cycles regularly.

What to do if not ovulating when using ovulation test strips?

  1. First check that the ovulation test strips you are using are in date ie not time expired, and that you are following the ovulation test procedure correctly, testing at the right time of the cycle and that you have a control line visible on the test to show that the ovulation test strip has absorbed enough urine.
  2. If you think that you are not ovulating, then you should talk to your doctor as you may have an ovulatory disorder ie ovulation is not occurring at all, or occurring only very occasionally. The good news is that ovulatory disorders are treatable. Clues that you may have an ovulatory disorder are very irregular or erratic menstrual cycles.

How accurate are ovulation test strips?

Urine ovulation test strips detect the LH surge that is the trigger to ovulation occurring. Ovulation usually occurs 1-2 days after this. When used correctly ovulation test strips are approximately 99% accurate at detecting this LH surge.

However this does not guarantee that ovulation will occur, it just shows that the LH surge has occurred. It is possible to have an LH surge and yet still not ovulate. In this case, there is usually a problem with the ovaries that is preventing the release of the egg.

Do ovulation test strips work for everyone?

Ovulation test strips will work for most women who are trying to conceive, and are a very accurate, affordable and reliable way of predicting when ovulation will occur. However there are some women with health conditions, for whom ovulation test strips may not work.

Ovulation test strips work best for women with reasonably regular menstrual cycles. If you have a very erratic and unpredictable menstrual cycle, knowing when to start testing with the ovulation strips can be very difficult and frustrating.

Erratic menstrual cycles are most likely to occur in women who are approaching menopause or perimenopause, or those who have Polycystic Ovarian syndrome. If you periods are very erratic and unpredictable,  and you are trying to conceive, it is wise to consult your doctor at an early stage, as conception can be more difficult under these circumstances, and erratic cycles can be a sign of ovarian failure. 

Women with Polycystic Ovarian Syndrome and who are approaching menopause, can also have permanently elevated levels of LH which makes using ovulation test strips confusing, and not very helpful. There is more information on causes of a prolonged LH surge below.

What does a prolonged LH surge mean with ovulation test strips?

Normally the LH surge last about 2-3 days. If it is regularly longer than 3 days then there are several possible causes to consider.

Causes of prolonged LH surge on ovulation test strip:

  • Anovulation
  • PCOS
  • Approaching menopause.
  • Another possible cause of a prolonged LH surge is an early pregnancy.
  • It is also worth noting that if you are using ultra-sensitive 20mIU ovulation test strips then the LH surge may be detected for longer than if you are using the 40mIU LH tests

How long after having a coil IUCD removed will I detect an LH surge with an ovulation test strip?

Most coils and IUCDs now contain a hormone that means there may be a delay in ovulation and in the periods restarting. This delay in ovulation is very variable and may take several months and when the period do restart, the cycle may be very erratic, to begin with. This can make it difficult to use ovulation tests in the immediate months following removal of the IUCD (coil). In some cases, the periods do not restart and you may just find that you are pregnant.

The control line on my LH ovulation test strip is faint. Does this matter?

The colour of the control line on an LH ovulation test strips can vary from batch to batch, and from brand to brand, and also on the time of day that you test and the dilution of the urine.

As long as the test line is as dark or darker than the control line the ovulation test strip result is positive. 

If you are unsure how to interpret your ovulation test strip result please e-mail us a photograph and your order number so we can advise you.

What time of day should I do an ovulation test?

To ensure the ovulation test result is optimum try to always do your ovulation test at the same time of day, and restrict your fluid intake for 2 hours before collecting and testing your urine with the ovulation test strips. 

The best time of day to do an ovulation test is early to mid-afternoon, ideally, between 2 pm and 2.30pm If you test at other times, you may completely miss the LH surge.

What are professional ovulation tests?

Professional ovulation prediction tests include cassette kits, ovulation tests strips, midstream ovulation tests & ultra sensitive ovulation tests that are available in bulk packs for doctors and clinics. They are cheap yet highly accurate ovulation test strips from ALLTEST

We also have an extensive range of professional pregnancy tests in strip, cassette and midstream formats that can be ordered in for fertility clinics, healthcare professionals, fertility practitioners & NHS at great value for money prices.

Contact us for professional & NHS ovulation test strips & professional pregnancy tests.

Wholesale & NHS ovulation test strips

Do ovulation tests work if you’re pregnant?

During pregnancy, you may still get a positive ovulation test. This is because LH is still released during early pregnancy and in fact, the pregnancy hormone beta HCG is very similar to LH hormone. During late pregnancy LH hormone is inactive. Pregnancy can be a cause of a prolonged LH surge.

If you think you may be pregnant this should be confirmed with a pregnancy test.

Will my ovulation test be negative if I’m pregnant?

  • Not necessarily.
  • As discussed above you can get LH released during early pregnancy, and the pregnancy hormone may sometimes give false positive on an LH test as the two hormones are very similar.
  • If in doubt do a pregnancy test

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Ovulation test strip FAQ page last reviewed and updated 14/11/23 by Dr Kate Garside

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