I have been on the Mirena for a year and my periods have been regular just alot lighter and lasting sometimes around 10 days. Last saturday was around when I was suppose to start my period but I just had a little light bleeding when I had wiped. Since then I've been very bloated and crampy but no bleeding and it's been almost a week. What scares me is the only time this has happened to me is when I got pregnant with my son. The mirena is still there but could it have moved and not be in right anymore? Have you ever heard of someone getting pregnant on it and not had a miscarriage?