L.D.
If you have any concerns, I highly suggest calling your doctor. They WANT you to call them with questions like this and if they don't, then I suggest finding a new doctor.
While a similar thing happened when I had my son (my third) 5 months ago, it only lasted about a month in total. I don't believe it is normal to have it last 4 months with only a week or two reprieve even if it were your cycle starting over. Are you nursing?
I would call the doctor without a second thought just to make sure.
Hugs,
L.