Bleeding

Me and my boyfriend had sex a couple of days ago and i have been slightly bleeding ever since. it’s not heavy or a lot but it’s noticeable every time i wipe down there. this has never happened any time i have had sex and nothing has changed about the way we had sex. he came in me this time and i don’t know if that could possibly cause the bleeding or not (???) i just don’t know why i’m bleeding when this has never happened before