Hi there. I was recently diagnosed with Celiac but only through a biopsy. It was a super simple procedure and it is 100 percent positive. My Dr. said it is the only way to be completely sure. Initially when I came out of the procedure he said that everything looked perfect and he did not think I had Celiac. I felt a little foolish for having the test done because my only symptom was fatigue and bloating. he called me a few days later though and said he was so surprised at my positive result. I had been gluten free for 7 months and I still showed up positive.
This, however is not recommended as it may interfere with your result.
I would have it done and get it crossed off your list. Then you can move on and know for sure. It's the not knowing that is frustrating.