HELP ! MY PERIOD DISAPPEARED???

Tai • Artist & Student from Atlanta 🌻✨
So guys I'm super confused 🙃 I've had an IUD since December of 2015. Up until around this point I've noticed my period getting shorter and shorter until about the past 3 months. I have had no period at all! Is this normal for an IUD? I have an appointment but I was just curious. I've taken six pregnancy tests that have all come out negative. I've just stopped bleeding