Maybe pregnant

So I have the iud and I was recently in a relationship and we never used condoms. After we broke up I slept with someone else within the same month. The other guy (who I slept with once) never finished. But today I am 7 days late on my period. I am freaking out because I don’t not even talk to my one night stand guy but I’m starting to get back at it with my ex. How possible is it to be the one night stand guys than to my ex? I’ve also had my iud over a year and really haven’t used condoms at all on top of all this I’ve never been a whole week late