brown discharge

every time i have my period i have brown discharge and i dont kno y my period only last for 3 days its some times waterey......... help pleasesad

are you on the pill or anything 

no im not i was but im not on them any more i am on adhd medication but hasnt been long

srry no im not on anything but medication adhd and havnt been on it long i had a string down there and it riped some how and it bleed alittle and i dont kno what it was either...... thanks for trying to help