HELP: Worried I Might Be Pregnant

So, I'm sexually active with my boyfriend and we had protected sex one day before my period started. He pulled out + wore a condom the whole time and we tried to make sure absolutely no semen got near my vagina by hand or something like that. My period came and went fine, and we haven't had sex since then. But recently my uterus has felt... the only way I can describe is it tight. It is bloated and I have a little bit of discharge. I think I'm just paranoid, but its absolutely not possible for me to be pregnant right? Since I had my period in between the sex we had and now? or is it possible? its too early to take a test, but I feel like I'm insane for worrying about this, but I'm 17 and CAN NOT be pregnant. Help!