Possible chance I’m pregnant.

Hello , there’s a possible chance I could be pregnant!! I had Sex 1 Day Before My Fertile Week starts I had sex In the morning ! Later that night this guy I’ve been talking too he came back from Texas. We had sex that night Unprotected , we was drinking , I’m not sure if he came in me or what happened! We had Sex the next day (Christmas) & the next day after that. Then I started bleeding again (the day I left) I was thinking. His penis knocked my period back on. If that’s possible ! My stomach was cramping & hurting extremely bad ! I took medicine & pepto bismo. The little second period situation lasted about 2-3 days. NOW!! My period suppose to be starting in 2 Days! I’m kind of scared, there’s a chance I might be pregnant. But how should I bring out to the guys? How would I know ?