If you can set your watch by the breakout on your chin, you're not imagining it. Hormonal acne before your period is one of the most predictable skin patterns there is — it follows your cycle almost to the day. The good news: because it's predictable, it's also treatable. Here's what's actually happening under your skin in the week before your period, how to tell it apart from other acne types, and the lifestyle shifts and in-clinic treatments that make a real difference — av