When an egg is released from an ovary it is caught in the fimbriae, enters the fallopian tube and is carried slowly along by contractions of the tube and by the rhythmic waving of tiny hair-like projections in its lining called cilia. Once in the fallopian tube the egg will await fertilization by a sperm.

During your reproductive life your ovaries release ova in cycles. Each of these ovarian cycles lasts about 28 days. The development and release of an ovum ready for fertilization by a sperm is called ovulation.

In the first half of each ovarian cycle about 20 ova begin to ripen and occupy fluid-filled sacs (follicles).

One of these follicles outgrows the others, matures and ruptures and releases the ovum.

This happens around 14 days before the end of the cycle and is the time when your fertility peaks. The other follicles that had started to ripen then shrivel up and their eggs die.

The ruptured follicle becomes the corpus luteum which grows for some days and produces the hormone progesterone.

If fertilization doesn’t happen, the follicle withers away and a new cycle begins when the lining of the uterus is shed at the beginning of your next period.