What’s is wrong

So It’s been a minute since I’ve had sexual intercourse but recently I did and it was great but Halfway through my partner informed me that I was bleeding now my period had just ended a week prior and so I knew it couldn’t be that. So we stopped but the bleeding hasn’t stop I’m going on day 5 of bleeding but it’s not heavy I only noticed it when I go to the bathroom and wipe plus there’s a burning sensation while I urinate and I get extreme episodes of pelvic pain we both had a std screen they all came back negative so I’m at lost as to what is causing this