Why Use an Ovulation Test?
You can only get pregnant during a few days of your cycle, when an egg is released from your ovaries (this is called ovulation). But sperm survives in a woman's body for a couple of days. So knowing when ovulation is likely to happen can help you to determine when to have sex, and so, increase your chances of getting pregnant.
Ovulation is controlled by hormones; in particular, a hormone called luteinising hormone (LH), which can be detected in the urine. Levels normally increase about 24 to 36 hours before ovulation. Home-ovulation testing kits can accurately detect the rise, or 'surge', in LH that occurs before ovulation. You can then use this information to decide when to have sex or, alternatively, to avoid sex if you're using kits for contraception. This is however not as reliable as other methods of contraception.
Ovulation tests are no more than a guide to timing. They don't tell you whether you've actually released an egg, just that you have the hormonal trigger. Nor do they tell you that the particular egg is healthy, or whether all the other essential parts of the reproductive process are working as they should be.
You don't have to use an ovulation test kit to work out your cycle, as ovulation occurs in the middle of the menstrual cycle. However, the length of the cycle varies from woman to woman, and month to month, so kits can help to pin down more precisely when ovulation occurs, by looking for the changes in hormone levels in the body.
Ovulation tests, are one type of fertility test that can be useful in helping to increase your chances of conceiving, but don't actually measure how fertile you are, or whether you may have a problem.