I've been on a mostly gluten free diet for 3 years after finding it helped my stomach symptoms. is it possible to find out if i have celiac disease?

Perhaps: A mostly gluten-free diet may not be helpful for those with gluten intolerance but may be helpful for those with wheat allergy. The blood tests for gluten intolerance is accurate when a person is consuming gluten. Consider seeing an allergist to help you sort this out.

Good question.: If you are on a strict gluten free diet then the serological markers for celiac disease will be negative. It is important to diagnose celiac disease before going on a gluten free diet. Consult your doctor, and check dq2/dq8 to see your risk for celiac disease.