Bleeding After Sex Now Late Period

I’ve been having sex with the same dude for almost two months now. Sometimes we use protection sometimes we don’t. But almost every time we have sex I bleed after, he doesn’t do enough to arouse me, it hurts so bad when he first enters. Is this a sign of endometriosis? Or is he just not arousing me enough?

Now my period is late by a day and I’m freaking out that I’m pregnant because I usually get my period on time. All of my period symptoms have been normal. Could the bleeding have been implantation bleeding and?