What do periods do?

Okay, so periods are literally how your body cleans out your uterus so it can get ready for a possible pregnancy. It's like your body's monthly reset button.

Think of your uterus as a super cozy little nest for a tiny baby to grow. Every month, your uterus gets a soft, fluffy lining ready, just in case a baby shows up. If no baby comes along, your body is like, "Well, no baby this month! Let's clear out this lining and start fresh." So, that lining (which is blood and tissue) comes out through your vagina, and that's your period.

It happens pretty much every month for most people who have periods, from when you're a pre-teen until way into adulthood. It's totally normal and a really important part of growing up and your body working its magic.