I had a baby January of 2009 and in march 2009 I had the mirena put in. I have been having cramps for a long time but no period. But yesterday I started bleeding and it's been a little lumpy and I'm still cramping could I be pregnant?

It's possible, every now and then a woman will find herself pregnant due to the IUD slipping. Could be just a period. Since this isn't the norm for you, however, would be a good idea to have it checked by your doctor.