HELP PLEASE!

My boyfriend and I had unprotected sex and during it, he pulled out and thought he maybe came inside me because he felt it on his hands. I thought the wetness on his hands was maybe from me but he thought it was himself..... So we stopped and just made out for the rest of the night. I did start my period that night and it was right on time... Could I still be pregnant even though my period happened to start that night?