Post-sex period?

Hi everyone!

My boyfriend recently got home after a 6 week trip away. While he was away I started on the mini pill which I’ve been taking for a month.

The first day he got back we had sex without a condom - because I’m on the pill now. I started bleeding instantly afterwards, but my period was due so we figured it was just that.

But, the same thing happened today (two weeks later). TMI but it was like the semen that came out of me was bloody, and now I’m bleeding. I’m not sure if it’s just going to be a little bleeding or if I’m going to bleed for a week again.

Does anyone know what this could be?

I’ve used progesterone only contraception before (implanon) with no issues. Typically my period only comes every 4-5 weeks.

UPDATE: I’m still bleeding the day after, like a heavy period.