If only one lobe was removed, ythe nodules may grow at another one.
Go back to the doctor. I had the same thing happen to me in the space of a few months and had to have total removal of the thyroid.
You don't mention if you had all your thyroid out. It could just be scarring inside which can get a bit lumpy, but only the doctor will know by feeling it for you. Don't wait for advice from the forum. Best to get it checked professionally.