Every month, 1.8 billion people menstruate globally. For those people, managing periods is essential for strong reproductive and emotional health, social wellbeing and bodily autonomy. But a lot of people haven't been educated about periods or the menstrual cycle since they were kids — if at all.This episode, a period manual in four parts: How periods work, the different stages of the menstrual cycle, how to know when something's wrong, and whether to have a period in the first place.