No period, and then randomly getting one?

Amy

I’ve had the Mirena in for about a year but the last 4 months I haven’t had a period at all it just completely stopped,but I’ve been cramping the last week and took a test just to double check a few days ago it was negative.Then out of nowhere I started bleeding not super heavy but it’s a medium flow and my back and pelvic area hurts so bad and the cramps are unbearable 😭😭 is this normal?anyone else experience this?