14 days late

So my period is now two weeks late. I have had the Paraguard IUD ( the copper, non hormonal one) since May of 2017 and have never had any problems with it and have always had a consistent period since having it (the latest it’s ever been since is maybe four days.) So of course, I took a pregnancy test on Monday and it was very obviously negative. I’m going to planned parenthood tomorrow to figure out what is going on, but I’m freaking out a little bit and wondering if anyone else has experienced this. I know that some women stop having their period with some IUDs but I also know that that’s usually only the case with the hormonal IUDs. My period has actually been heavier and I’ve experienced more cramping, breast tenderness, etc since having the IUD. It may also be important to note though that before being on any type of birth control, my period was very irregular; I would have one every other month or so at random times. I’ve been on the pill and the patch which regulated my period and then the IUD, I don’t think I’ve been off of birth control since getting on it at 15. I’m just concerned and need some reassurance I guess 😭