Im 16, In the Beginging of April or late March i started having Brownish blood but i thought it was implantion bleeding and i was pregnant but i had a miscarrgie and i have been bleeding since then!! it was real light at first not even enough to fill a lite tampon, Then i stoped bleeding and had sex i started bleeding really bad while having sex. And ever since then i have been bleeding very heavily and i have had these really big dark red blood clots, and it doenst look good!!! the blood clots are most of the time bigger then the size of a quarter. Please tell me why i have been bleeding like this and what this could be! HELP ME