I stopped taking birth control over a year ago and i haven't had a normal period since then is that normal?

Depends.: It depends what you mean by "normal." some women have cycles that are longer or shorter, or heavier or lighter -there is a range of what is considered normal menstruation. If you are experiencing extremely heavy bleeding, painful periods, or have another concern, you should see a physician.

Menstrual disorders: If your periods were normal before starting the pill, they should go back to normal after a couple of cycles. Your body might have changed during the time you where on the pill. (not necessarily because of the pill). See your doctor for proper evaluation.