Bleeding after sex on iud

The last few months, I’ve been spotting starting two days after I’ve had sex. I keep feeling like it’s an issue with my iud. I got an ultrasound done about three months ago, and it came out normal. Not sure what the deal is. I’ll probably get checked again one of these days in case. Has anyone experienced this? I’ve had it for about a year. I’ve gotten breakthrough bleeding before but this seems to be a pattern and I’m not sure what’s going on. Sex doesn’t really hurt or anything. When I got the ultrasound, I could feel the tip of the device when I checked them, which is why I got the US in the first place.