"Hearst Magazines and Yahoo may earn commission or revenue on some items through these links." Let’s take a mental trip back to seventh-grade health class. When you got to the unit on menstruation, ...

New study shows that the lengths of menstrual cycles, follicular phases (before egg release) and luteal phases (after ovulation) are all variable. The luteal phase is importantly more variable than ...

Let’s take a mental trip back to seventh-grade health class. When you got to the unit on menstruation, you probably learned that people with uteruses typically get their periods once a month or so—but ...