Just wanted to add that another option for you would be to get the gene testing. If you're negative for the Celiac gene, then you cannot have Celiac - you most likely have gluten sensitivity. No need to do the gluten challenge. That said, I agree with the others that 1) your doctor is an idiot and/or ignorant and 2) you'd have to do a gluten challenge to get a reliable Celiac test at this point.
FYI, we have more than one biopsy proven celiac that does don't have those genes that post on this board.