Uterus feels "weird" after orgasm

Okay so for the past few days my uterus has been feeling very weird after I orgasm and I can't describe what it feels like.. It's been two weeks since I last had unprotected sex with DH but I was on and I don't think its possible to get pregnant but ive been reading around and a few woman say they got pregnant after having sex on their period.

I'm just nervous.

Do you think I could be pregnant? or is it just something else?