Paragard No Period?

So I've gone to my doctor and they can't seem to figure out what's wrong. Everything is in place and nothing has moved, but I've been getting weird periods for the last couple months. I got a normal one in august and had hit my 5 month mark in September for getting it  placed. I spotted and had a two week period in September- leading into October. October was late a week and lasted 4 days, then I spotted for a few more.. I'm spotting now, but it's mostly just cramps. I guess my main question is: has this happened to anyone else? Are they supposed to stop, even though I don't have BC with hormones?