Me and my boyfriend had sex last weekend. We used a condom and he took it off and he did cum but he pulled out. I missed 1 day of my birth control but I took it the next day. The pill I missed was a couple days before we had sex. I was supposed to have my period yesterday (Sunday) but I didn't get it. I didn't even get it today. I feel like I have very small cramps but I'm unsure. Could I be pregnant?