Help!

So things got a little carried away with this guy in the back of his car and as soon as he was inside me he pulled out and came everywhere. I asked if he came inside me and he said he didn’t know. I wiped myself with my hand and there was some cum but I don’t know if it got inside me. I’m

About to start my period in a few days and I told him I wasn’t paying for plan b if I needed it. I tried to get ahold of him and he blocked me. I don’t know what to do please help me. This has never happened to me and I was stupid enough to not use protection...