Many people today are putting themselves on a gluten free diet. This is OK if it is not permanent. Before you do this on a permanent basis you should verify if you are gluten intolerant.
If you were to go without gluten for a week and find your abdomen has reduced that is surely telling you something. It is possible you have cut out bread and now are not reacting to yeast.
The reason you should not go on a gluten free diet before testing is done by a doctor is that it can affect your tolerance for gluten. You need to be eating gluten when you have the testing for celiac disease (gluten intolerance).
That is because gluten affects the intestines of celiacs. If you have any doubt about being celiac or have any degree of gluten intolerance you should have testing done first before the gluten free diet.