How do you have a period

Every month or so, the uterus lining gets thicker to prepare for a fertilized egg if the woman becomes pregnant. If the egg doesn't get fertilized, that lining is released from the body as blood through the vagina. This monthly process is called menstruation or a period.

A period like biogically, first you need to be a girl and going thruogh puberty. Like having pubic hair growth, chest growth. and the period comes differntly for poeple but some get white stuff and they can start to tell it is coming but ask an female adult that is related to you but their signs.