Can i get pregnant if my boyfriend came in me 3 days before my period

I have a feeling that i should be okay but im still a little nervous about this, can i still possibly get pregnant? my period is due January 4th and we had sex the 31st and 1st and he came in me multiple times. Im going to take a plan B just in case but i still would like to know the possibility. I am 21 years old never had kids before.