Burning after sex

So tonight me and my boyfriend wanted to be adventurous so we had sex in his car. I’m on birth control but sometimes I take my pill an hour or two late. Tonight he came inside of me and I’m freaking out that I might be pregnant but I always take my pills and sometimes skip my sugar pills. Could I be pregnant?? Also I have this burning, not while I pee though. Please help and all advice. I’m literally panicking and it’s only been an hour.