i used to be on the pill for around three years maybe on and off and whenever i was taking the pill i never got my periods even when i came off the pill i never got them only a few drops for like 2 days within six months. i used to worry aswell but im now pregnant so i wouldnt worry at all
I would say go to a different doctor to get a different opinion...if your doc isn't doing anything about it. It does take some time after stopping the pill for your body to regulate.