bleeding while ovulating, help!!!

I had sex, and he came inside me while ovulating. The day after (yesterday) I began spotting and today it's like I am on my period, but it is darker blood.  I am super regular normally so this is confusing for me. We also had sex the day after I got off my period (11 days ago) so if for some strange reason I could have gotten pregnant then and this is implantation bleeding. Any insight?