Having a period is a normal, healthy part of becoming and being a woman. A period is the result of a cycle that takes place inside a girl’s body. This menstrual cycle makes it possible for women to have babies. The cycle begins with ovulation, when an egg is released and begins its journey.

During each cycle, one egg grows and is released from an ovary. It finds its way to the fallopian tube.
The egg moves through the fallopian tube toward the uterus. (If the egg and a man’s sperm meet here, a woman becomes pregnant.)
The lining of the uterus grows thicker. This lining is made up of blood, tissue, and fluid. (The lining will nourish a growing baby during pregnancy.)
About once a month, the egg and the lining of the uterus are shed through the vagina. This is called a period. (A period does not happen during pregnancy.)