blood after sex?!

Jocelyne
My SO and I just finished having sex and when I went to the restroom, I wiped and I saw a tiny bit of bright red blood. It was when I first wiped so there was a bunch of lube in the toilet paper too. So I kept wiping and there was no more blood. I'm on the IUD, idk if that could cause it too... I just wanna know if this has happened to anyone?