When Does The Puberty Starts Having Discharge And Abdomen Pain?

hi um im just wondering but do you think you could tell me when my first period will start? i have lots of discharge and hair down there and a little under arm im a 34 a and i have most symptoms like headach lower stomach ach near the adoman ( i donno how to spell it) lower back pain i am turning 14 in 3 weeks. i have mood changes and feel irritable i get mad or upset for no random reason. my mom started when she was 15 or 16. i am well active i have dance 2 nights a week and basket ball on the same nights sometimes more. i am very fit.i am really nervous-_- i have the stomach back and head ach every month now around the 26 please if you can help