Young people can reproduce at the end of puberty. The age when this occurs varies but it nearly always happens before boys and girls have left school. In many countries there are laws governing the age when a young person may consent to sexual intercourse. In Britain the minimum age is 16. It is important to consider all of the possible consequences before engaging in sexual activity with another person.
Many adults use contraceptives to enjoy sexual intercourse without the woman becoming pregnant.
Some types of contraceptive also reduce the chance of spreading sexually-transmitted diseases. The menstrual cycle is a monthly sequence of changes that prepares the female body for conception and pregnancy. This cycle repeats itself about every 28 days until either conception occurs or the child-bearing years end with the menopause at about the age of fifty. Eggs are made and stored in the ovaries of a woman. About every four weeks an egg, sometimes called an ovum , matures and moves from the ovary where it was stored, down a Fallopian tube to the womb.