Please help! Could I be pregnant?

Ok, so two nights ago was my friends birthday party and I got drunk and a little high, I started talking to my ex (he was my first kiss and the first person I had been fingered by) and suddenly we were making out, eventually things got heated and I had given him a blowjob already and he came, but then we both kind of decided to go further, unfortunately neither of us had a condom or any protection as I’m not on the pill and we both tried to put his penis in and it was very sore (this is the first time I would’ve been having sex) I can’t really remember if it did even go in and I did give him another blowjob but I can’t remember if it was before or after we ‘had sex’ but he did come then again, also I was on the first day of my period, do you think that there is anyway I could get pregnant, maybe even from a little bit of sperm left from the blowjob? Help, I’m really nervous