I got over my period about 6 days ago, and started birth control that same day. Since then I haven't had any oddly colored discharge or anything like that. I had unprotected sex with my boyfriend last night . He didn't come anywhere near finishing before we stopped. I woke up this morning with a heavy amount dark brown discharge in my panties, and it is still coming out. I'm unsure whether or not this is just leftover period blood making its way out of me, or implantation bleeding?