Note that the current blood test for celiac disease will give a false negative if you haven't been eating wheat and have been avoiding gluten for some time, so

Note that the current blood test for celiac disease will give a false negative if you haven't been eating wheat and have been avoiding gluten for some time, so it's perfectly possible to be celiac and be diagnosed as definitely not celiac if your doctor doesn't know this (which many don't.) Even a probe examination of the small intestine may give you a pass if you have been avoiding gluten for, say, months. The expected damage won't be there.