During each menstrual cycle a single egg will develop and mature in the ovaries. Ovulation is the time when this mature egg is released into the fallopian tube. This usually happens around 14 days after the first day of the last menstrual period and a woman is only fertile for a few days around the time of ovulation – this is why it is important to know when ovulation occurs!
For women who want to become pregnant the best time to have intercourse is 1-2 days before ovulation, or on the day ovulation occurs. In this way sperm will be released into the vagina and travel towards the egg at just the right time. This period gives the best chances of fertilisation and therefore pregnancy.
The process of ovulation is triggered by the release of a hormone from the brain called Luteinising Hormone (LH) and the levels of the hormone increase significantly in blood and urine about 1-2 days before ovulation. The most reliable and accurate ovulation home test is the one that measures this increase in LH and by doing this it can tell a woman when she is going to ovulate. The hormone, LH, causes the egg to be released into the fallopian tube in readiness for fertilisation.
During the few days after ovulation the egg will travel down the fallopian tube to the womb. It stays there for two or three days and if it is has not fertilised it dies and is expelled with the womb lining at the start of menstruation, usually 12-16 days later.