Unusually Heavy Period on IUD

I got my Kyleena IUD put in almost two years ago and my periods had a typical cycle until recently. I had one period only last 3 days (normally it’s 7-10) and then the next one was over two weeks of a bit heavier spotting. Then this period was normal for the first week and when I thought it was going to end I started a period that was heavy like the ones I used to have before I got the IUD. (I also don’t have any pain) I have an appointment with my doctor but it’s not for two weeks - and of course this morning I scared myself by reading that this can happen if it’s out of place. Has anyone experienced this? And if so what was the cause?