Yes, it could be non-celiac gluten intolerance, which is about six times more prevalent than actual celiac disease (supposedly it is not an autoimmune response - and I say supposedly, because they don't know much about it yet). Or it could be a false negative, or you may not yet be making sufficient antibodies to measure yet. Or it is most likely that after two weeks of very low gluten before testing, that enough healing had taken place that the antibodies they test for had retreated
If you have been gluten lite for only a month, it has not been enough, or long enough to feel the full benefits yet. Keep up the diet and I believe you can get back to 100% whether it is actual celiac or non-celiac gluten intolerance.
At this point testing by the GI is probably not going to help because you have a month of healing and even the biopsy could well be falsely negative at this stage and you would have to do a gluten challenge to be accurately tested.
Is there a test to confirm gluten intolerance? I'm tempted to do gluten OD for the next 12 days before my GI appt. and have them re-test me. It's driving me nuts not having a clear answer, and it's so expensive every time I have to go to the doctors. I wish they had a policy where you don't pay until they give you a diagnosis .