I would go to a doctor and tell them your symptoms. I was your age when I was diagnosed with pcos and had a similar thing with the one time period in middle school. Do you have any other symptoms indicative of pcos? Dark underarms, dark neck patches, excess hair, skin tags, etc. It's worth going to your doctor to get checked out.
Go to the doctors and catch what ever it is early so you don't go through heart ache with it early also it can make you gain weight and its hard to shift but if you catch it you can control it