Ugh, sometimes it is hard to figure out. If you are young, being irregular is pretty common. But I don't know why this month you had an early period. I would see if it happens again or if it is a fluke. Do you go to your ob/gyn or planned parenthood for an annual pelvic exam and discussion about your reproductive help with your doctor? If you haven't been in a while, why don't you plan that visit and discuss your irregularity.