Menstruation is also called ‘having your period’. It is the time of the menstrual cycle where the blood and tissue lining of the uterus come out through the vagina.
During puberty, the ovaries start to mature eggs to get ready for reproduction. As this is happening, the lining of the uterus builds up with tissue and blood. The ovaries then release one, or sometimes more, of the eggs into the fallopian tube. If sperm are in the fallopian tube, the egg may get fertilized. The fertilized egg travels down the fallopian tube to the uterus where it implants into the lining. This is a pregnancy. If the egg is not fertilized, it dissolves in the fallopian tube and is reabsorbed by the body. This tells the uterus to move the built-up blood and tissue out of the uterus through the vagina. This is called menstruation or having a period. A person’s period usually lasts 3 to 7 days. The time between the beginning of one period to the next is called the menstrual cycle. A menstrual cycle lasts about 24 to 38 days but can vary from person to person.