I am sexually active (only had one partner), I am on birth control, Its been three weeks since i have had sex, I had my period last week and now it has only been a week since my period and now i have this brown discharge. Now i know it is the middle of my period (kind of) but this has never happened before, and ive had my period since the 5th grade and i am now in college. I just want to know if this could be a disease or something. Thanks.