Help! Scared of pregnancy

I had sex with a friend and he was certainly bigger than I was used to. Near the very end, he finished inside me but neither of us had realized the condom had slid off inside of me. I also take birth control but I forgot to take it the day before. So:
Monday: took pill
Tuesday: skipped
Wednesday: took pill at 11am (had sex that night) and took pill at 11pm
Thursday: took pill at 11am
Do you think it makes much of a difference??