What Causes Delay In Menstruation And Abdominal Cramps?

Hi, I am 17 years old and just lost my virginity. Me and my boyfriend used an condom and he did not ejaculate inside me. he couldn't keep an erection so we had so start and stop checking the condom often. He didn't ejaculate until 30 minutes after intercourse. I can't imagine when or how any semen could have entered me. I am 5 days late for my period. I get strange cramps in my abdomen and my left side of my abdomen hurts really bad. I'm always hungry and my breast are a little tender. I show no signs of pregnancy. and I'm terrified. What is wrong?