Me and my ex had sex on black Friday he has had a vasectomy and didn't cum and he wore a condom. I…

Me and my ex had sex on black Friday he has had a vasectomy and didn't cum and he wore a condom. I also have an iud. But I've been having all these cramps in my lower stomach he no sperm got around me at all. And he's also shown me there were no holes in the condom t leaks by filling it up with water. My period is due on the 12th but I don't normally start having cramps till the day before. I know realistically there's no way I'm pregnant but I've been stressing my self out just thinking it's possible. And the internet doesn't help calm that down either. Does anybody know what these cramps could be I never had had them before sometimes they're right in the middle other times they're on the right or left side