Your menstrual cycle is defined as the days from the start of one menstrual period to the beginning of the next one - the average cycle is 28-32 days. Ovulation is the fertile time of your menstrual cycle during which time one or more eggs are released from the ovary and pass into the pelvic cavity through the Fallopian tube.

If you are trying to get pregnant, you should have sexual intercourse around the time of ovulation. Sperm cells can live for 2-3 days but an egg survives only 24 hours after ovulation, unless it is fertilized by a sperm. Therefore, it is recommended to have sex one or two days before ovulation until one day after ovulation.

This method is not foolproof, so it should not be used as a means of birth control. Depending on your body’s cycle and other factors which could affect it, such as illness or medication, ovulation could occur before or after this estimated time. The only reliable way to avoid becoming pregnant is to use proper birth control measures.

Trying to get pregnant? Use this to help determine your most fertile times.

Average length of cycles:

Luteal phase length: