What are the chances?

If I had sex over 2 weeks ago on like July 1st and again last week on the 10th (both times we used a condom the whole time, he didn’t even finish, checked the condoms there were no holes, and I take the pill everyday) except the second time we had sex I was taking an antibiotic. My period is due in 3 days and I’m feeling slight pains in my uterus every so often. Am I pregnant or it because I’m getting my period??