breakthrough bleeding??? HELP

Okay so I got on BC pills last August because I became sexually active. My then boyfriend and I broke up back in September. I’ve continued taking my BC pills, even though I haven’t been sexually active since. I’ve been bleeding for about 9 days straight. Not heavily, but just enough to freak me out. It’s brown, dark, old blood. I’m not going to lie, I haven’t been taking them like I should. But my period is supposed to start today. I don’t know if I’ve been having breakthrough bleeding or if I’ve been on my period??? I’m so confused and scared. Nothing like this has happened before. Someone please help. Thanks.