How Ovulation kits work

Short Answer: Ovulation kits test your urine for certain hormones.

There is only a short ‘window’ in each cycle during which a woman is able to conceive. So, for those attempting to get pregnant, being able to pinpoint the correct days can be extremely helpful. The day of ovulation and the couple of days prior make up your ‘fertile window’. Ovulation test kits are an easy way in which to take some of the guesswork out of finding these fertile days.


Most ovulation kits come in the form of a short stick, somewhat resembling a pregnancy test. You use it in the same way as a pregnancy test as well. Either, pass the stick through your urine stream or dip the stick into a sample of urine, collected in a clean container. Coloured bands will then show up on the stick to give you the result. Using an ovulation kit every day is likely to get expensive quite quickly. It’s a good idea to try using them 5-7 days a month. Try using our ovulation calculator to help work out when you’re likely to be ovulating, then start using the tests a few days before the date the calculator gives. Once you have a positive result, your fertile window has started; having sex in the next 2-3 days will maximise your chances of conception.


Ovulation test kits work by testing your urine for an increase in luteinising hormone (LH). There is always a small amount of LH in both your blood and your urine, but just before ovulation these levels will surge. This is what the test is looking for. Since the LH surge occurs a couple of days before ovulation, it coincides with (approximately) the start of your fertile window.


Of course, many women get pregnant without the use of ovulation tests. However they can be really useful in some circumstances, for example:

  • Couples with very busy schedules or who have to travel a lot and do not have time for regular sex.
  • Women whose periods are irregular can find pinpointing their fertile days to be very difficult.
  • Couples who have been trying for a while but haven’t been able to conceive.

For all these people, the kits can be a really useful way in which to speed up the process.


If you are still unable to get pregnant, even after using ovulation tests to find your fertile days, then try asking your doctor for advice. When doing so, mention the fact you have been using ovulation tests as this can help to rule out some possible underlying problems.