Skipped period on IUD

A

So, this is the first time that I can recall my period skipping while Ive had my IUD. I've had it for 2 years now and I've always had light periods while on it. This past month my period never came. I checked for my strings and they're there, I'm not too worried about being pregnant but it's still freaking me out. Has this happened to anyone else with an IUD?