FAQs Ovulation Tests

Frequently asked questions for Ovulation Tests

  • What is ovulation, when does it occur and why it important?

    Whether you are thinking about trying for a baby or trying already, gaining a better understanding about how your body works can be a big help. One in two couples could be trying to conceive on the wrong days of the woman’s cycle4, so we’ve put together some information to help you understand your menstrual cycle and the ovulation process. Ovulation happens when hormone changes trigger your ovaries to release an ovum (egg) – usually 12 to 16 days before your next period starts. You are most fertile on the few days leading up to and including the day of ovulation.

    The ova (eggs) are contained in your ovaries. During the first part of each menstrual cycle one of the eggs will be prepared for release from the ovary. As you approach ovulation, your body produces more estrogen. This hormone causes the lining of your uterus to thicken and also creates a sperm friendly environment. The higher estrogen level triggers a sudden rise or ‘surge’ in luteinising hormone (LH) which then triggers the release of the egg from your ovary, this is called ovulation.

    Normally, ovulation occurs 24 to 36 hours after the LH surge, and you are at your most fertile on the day of the LH surge and the day after.

    The egg survives for up to 24 hours after ovulation which is when it can be fertilised. If fertilisation does not occur, the levels of the fertility hormones decline and the next cycle starts with the shedding of the thickened uterus lining (period).

    Although the egg only survives for up to 24 hours, sperm can survive for up to five days. That is why you can still conceive even if you have sex 4 -5 days before the egg is released.

    4 Johnson SR, et al. Foster L and Ellis J. Human Reproduction (2011) 26: i236

  • I think I might be pregnant. What should I do?

    You could take a Clearblue Pregnancy Test. They’re easy to use and can give you an accurate result in as little as 2 minutes. If your Clearblue Pregnancy
    Test result is ‘Pregnant’ you should see your doctor to discuss your result and the steps you should take next.
    If you’d like to know more about Clearblue Pregnancy Tests, click here.

  • I've done all the tests as instructed, but I’ve not yet detected my LH surge. What should I do?

    The number of tests in a Clearblue Ovulation Test pack is sufficient for most women with regular cycles to detect their LH surge. If your cycle length varies by more than 3 days, then you may need to start a new pack and use additional test sticks to detect your LH surge. Some women do not ovulate each cycle and therefore will not see an LH surge in such cycles. If you are concerned about your results please see your doctor.

  • Do I need to use all Clearblue Ovulation Tests?

    No. You can stop testing when you detect your LH surge and store the remaining tests in case you need them next cycle.

  • Do I need to compare my daily Clearblue Ovulation Test results?

    No. Each test that you do will tell you your fertility status for that day.

  • I made a mistake during ovulation testing, what should I do?

    The best solution is to use another ovulation test again as soon as possible today (though you should wait 4 hours before passing urine again to ensure that the level of fertility hormones in your urine is not diluted). Try to avoid drinking excessive amounts between doing the ovulation tests. Make sure that you follow all the instructions carefully. It’s best not to wait until the next day to do another test, or you could miss detecting your fertile days. If you have collected a sample to test, then you can use this same sample straight away to do your second test. If you don’t detect your LH surge with this second test, then test again tomorrow at the usual time.

  • What are the highest and lowest fertile days?

    The days during each cycle when you are most fertile, and therefore most likely to get pregnant from unprotected sex, are the day of ovulation and the day before – these are the 2 days of peak fertility. There are also a few days before this when you experience high fertility and you also have an opportunity to get pregnant. Outside this ‘fertility window’ of about 6 days, the chances of getting pregnant are low.

  • What are the differences between ovulation and fertile days?

    'Ovulation' is the process of an egg being released from an ovary within the woman's reproductive system and this happens 12-16 days before the next period starts. A woman is at her most fertile on the day of ovulation and the day before.

    The 'fertile days' are all the days during a woman's menstrual cycle when she has the ability to become pregnant if she has unprotected sex. Due to the fact that sperm can survive for several days in a woman's body during her fertile time, a woman will have typically 6 fertile days each cycle, the day of ovulation and the 5 days before that.

  • Why do I need to know my cycle length?

    The timing of ovulation varies according to your cycle length, so to find out when you’re most fertile, you need to know your own body and cycle. You can work out the length of your cycle by counting from the first day of your period (Day 1) to the day before your next period starts. Ideally you’ll have this information before you start using an ovulation test.

    Cycle lengths differ from woman to woman and cycle to cycle but are usually between 23 and 35 days long.

  • How can I find out when I’m most fertile?

    There are a number of ways that you can find out when you are most fertile, one of the most simple and accurate is by using home ovulation tests such as Clearblue Ovulation Tests.

    Clearblue Easy Ovulation Test or Clearblue Digital Ovulation Test help you pinpoint the 2 most fertile days to conceive naturally, by detecting your LH surge.

    Clearblue Advanced Digital Ovulation Test is the only ovulation test that typically identifies 4 fertile days…2x any other ovulation test. It tracks the changing levels of both LH and estrogen and its smart algorithm adapts to your personal cycle.

    2 2In the first 2 cycles of use. Robinson JE., et al. Fertility and Sterility (2007) 87: 329-334

  • Do you have any tips to help conceive and have a healthy pregnancy?*

    The following tips will help you to give your baby a good start in life:

    • Take folic acid Taking folic acid before you become pregnant is extremely important as it means that there is enough of this essential vitamin in your body at the very earliest stages of pregnancy. Taking folic acid early can prevent neural tube defects (problems with the development of the spine, such as spina bifida).
    • Go for a physical check up Review your lifestyle e.g. alcohol and cigarette consumption, current medications and vaccinations, and ask your healthcare professional for general advice about getting pregnant and pregnancy.
    • Be a healthy weight Being overweight or underweight could cause difficulties in conceiving. Talk to your doctor if you need help to know the best weight for you, and for advice on how to achieve and maintain that weight.
    • Get enough exercise This will help to tone and strengthen your muscles and make it easier to carry your baby. Once you are pregnant, ante-natal exercise classes are a good way to stay healthy as they are specially designed for pregnant women.
    • Boost your nutrition Your baby’s only source of nutrition will come from you. So make sure you get enough calcium, protein, vitamins and carbohydrates throughout your pregnancy. Avoid caffeinated drinks and unpasteurised dairy products.
    • Be mindful of medication Discuss any prescription or over-the-counter medications that you take with your doctor.
    • Avoid infections (for example toxoplasmosis) Always wash your fruit and vegetables, wear gloves for gardening or emptying litter trays and make sure your meat is thoroughly cooked.
    • Keep your dentist in the loop If you need dental work, let your dentist know you’re pregnant. Some treatments could be harmful to your baby.
    • Stay safe at work The guidelines on safety at work for pregnant women are very variable from country to country, so you should consult the professional organisation that are responsible for giving advice on this subject where you live.

    *These are only suggestions for information purposes only. Always consult a qualified healthcare professional for medical advice, in particular to monitor the progression and duration of your pregnancy. Please always read carefully the instructions provided with the product before use.

  • What are the chances of getting pregnant during the fertile days?

    The chances of getting pregnant will vary cycle to cycle and woman to woman and will be dependent on many variables such as the woman’s age, her partner’s age, their general state of health and lifestyle. In a study3, the chances of getting pregnant on each of the days during the fertility window were reported and are shown in the graph below:-

    3 Wilcox AJ., et al. NEJM (1995) 333: 1517

  • I've recently stopped taking the contraceptive pill. Does this affect my result?

    No, it will not affect your results. But your cycles might be irregular if you’ve recently stopped taking the pill, so it may be harder to know when to start testing. For this reason, it might be a good idea to wait until you’ve had two natural menstrual cycles in a row, and note the length of these cycles, before using a Clearblue Ovulation Test.

  • My cycle is outside the range shown in the table. How will I know when to start testing?

    If your cycle is 21 days or less, you should start testing on day 5 of your cycle. If your cycle is longer than 40 days and you are using either Clearblue Easy Ovulation Test or Clearblue Digital Ovulation Test, you should start testing 17 days before you expect your next period. If your cycle is longer than 40 days and you are using Clearblue Advanced Digital Ovulation Test, you should start testing 20 days before you expect your next period.

  • I've used Clearblue Ovulation Tests for several months and haven't got pregnant. Can I be sure of getting pregnant?

    It can take normal, healthy women many months to conceive. There are many reasons why you may not get pregnant, even if you've made love at your most fertile time. So keep trying. If after several months of trying you've had no success, it’s advisable to go to see your doctor to find out more about your next steps.

    In the UK, your doctor will usually expect you to have been trying to get pregnant for a year if you are under 35 yrs old or for 6 months if you are 35-40 years old, before he will consider further investigation. If you are over 40 years old then you should ask for advice immediately.


Digital Ovulation Test: pinpoints your 2 most fertile days

In every cycle there are only a few days when a woman can conceive, so having sex on these days is very important if you are trying to get pregnant.


Advanced digital ovulation test

In every cycle there are only a few days when a woman can conceive, so having sex on these days is very important if you are trying to get pregnant. The Clearblue® Advanced Digital Ovulation Test is the first and ONLY test that typically identifies 4 or more fertile days each cycle.