Ovulation is the release of a mature ovum (egg) from an ovary. The release enables the egg to be fertilized by the male sperm cells. It occurs about every four weeks, approximately 14 days before the start of the next menstrual period.
If the egg is not fertilized, it will degenerate. The uterine lining that had built up in preparation for the fertilized egg will then slough off and menstrual bleeding will begin about ten days after ovulation.
Occasionally, cycles occur in which an egg is not released; these are called anovulatory cycles. A woman can get her period even though she is not ovulating.
