Bleeding for the first time

Claire

I have the Mirena IUD. After I got it, I stopped having periods completely, but now (a year and a half later) I had a little blood. It wasn’t like full on period, but it could just be the start. I have also been having some cramps for the last couple days. Is it normal to randomly get a period when I haven’t been for a long time, or should I be concerned?