ouch!!

Hey loves! I have the mirena and have for about 6 months. My period has been irregular and if anything I have had it for 2 days and the blood is very dark. Recently it has gotten a little more regular, few days once a month. It was regular this month, stopped for a day, and now is really fresh blood and more than usual. I have bad cramps and my back hurts. Know this is normal, but need some reassurance. This happened to anyone else?? Thanks!