Aday and a half period, what does it mean?

I'm not sure but I've had my period for a day & a half.. & the last time I had sex was last month (August) I'm not sure what it means... I don't even know if my boy friend Cummed in me or accidentally did a little but we did it unprotected every time we had sex.. So i don't know how much cum it takes to get pregnant also my boobs and back has been sore. So confusing..