i am 17 years old, i'm on the depo shot. i've been on the shot for almost a year now. after 4 months of using the shot my periods started to be irregular. i got streap throat at the begging of feburary and my doctor had given me anitbiotics. i had unprtected sex after a week of using the antibiotics and i started bleeding in the middle of intercourse. i thought it was my period, but now i'm starting to wonder and i'm a bit worried because my period has not stopped since then. it was heavy that night, i woke up the next morning no bleeding for he next two days, then i started bleeding again, it gets lighter then heavier and stops sometimes for a few hours to a day, then starts again. why am i having a period this long ? i know it's not a misscarriage. i've had one before and i had only bleed for a week. please help. thanks.