Do I have a STI or am I just paranoid

Ok long story short I had sex with a guy Saturday night and Sunday morning. To be clear I was drunk Saturday but it was all consensual.

We apparently ran out of condoms because they kept braking so we said fuck it and keep going. I was at the end of my period and a bit dry and now (Monday) I’m in quite a bit of discomfort. I’m bleeding and it’s pale and a little creamy.

I’m positive he did not finish in me but I do have a plan B around just to be safe. Oh and I’m on the pill. I’m normally a lot more safe than this it was just a fluke.

The other thing I’m worried about is if this could be an STI. He doesn’t seem like the type but you never know…. Should I go to the wellness center on campus or just wait it out?