As Scott said, if you go on a gluten free diet ahead of testing you can expect the test results to be negative. If you remove gluten from your diet, the inflammation in the lining of the small bowel will subside, antibody levels (what the blood tests are checking for) will drop and the mucosal lining will experience healing such that a biopsy will be normal. So, it makes no sense to me to start the gluten free diet now unless your doctor wants to see if the weak positive disappears in response to a gluten free diet. Your Marsh 1 score indicates little to no damage has been experienced in the lining of the small bowel to this point. Two slices of bread daily might not be sufficient to produce unequivocal test results. Recently revised "gluten challenge" guidelines are recommending at least 10 g of gluten daily (about the amount found in 4-6 slices of wheat bread) for at least 2 weeks leading up to the day of testing, whether it be the blood antibody testing or the biopsy. It makes more sense to me for you to increase your gluten intake for several weeks and get retested. It is not likely that doing so for that limited amount of time will produce any serious health consequences but may give you unequivocable test results and more clear direction. If you decide to do this, make sure that in addition to the tTG-IGA test, you request a "total IGA" test order to check for IGA deficiency. If you are IGA deficient, your tTG-IGA score will be artificially low. Those are, at the very minimum, the two tests that should always be ordered when a blood draw is done check for celiac antibodies. There are other tests which can be ordered as well that check for evidence in the IGG immunes response spectrum. Here is an overview:   

Awesome, thank you! 

This article has some detailed information on how to be 100% gluten-free, so it may be helpful:    

Thank you! Kind of starting to accept that, sucks but id rather switch to a gluten-free diet now than regret it later. I'll probably just listen to this Dr for now and go on a gluten-free diet, I have an appointment in May with a Dr that specializes in celiac so im hoping I will have a better experience there.

From the article regarding the tTG-IgA test: So the most likely explanation of your positive tTG-IgA test would be celiac disease.