Having period for 3 weeks+?

i started my period about a week after my last one. i thought it was because i was stressed out because of a breakup, but now it's 3 weeks later and i'm not stressed out anymore, but i am still bleeding. i moved back in with my dad, so i'm around my stepmom and i know girls seem to have their periods at the same time once they've been around eachother for a while. could this be it? also, i have hpv that came back, and i have pre-cancerous cells on my cervix, but i dont think it's cancer or anything yet.and i have been regularly taking birthcontrol for years, and i havent changed to a new brand or anything. thats all i can think of that could be contributing to the bleeding. its getting reeeeeeaaaalllllllly annoying. please help!