Bleeding after sex?!?!? Copper IUD

Sierra • 19, Toronto, caffeine dependent life form!
I've been sexually active for 5 years now with the same guy, and I've never had an issue with pain, discomfort or bleeding before. I got a copper IUD back in May this year and sex since has been more painful specifically in the "doggy style" position As well as recently when I've had sex right after there's blood there as if it were my period but I know it's not my period because it goes away after I clean up and there was no blood the next day. I'm wondering if my IUD is the cause behind this and if I should sex medical attention. Has anyone else has this problem?