Burning pain under right breast comes and goes. hist of gerd. 7wks pregnant. causes?

Costochondritis: If you are tender to the touch on the ribs, it may be inflammation of the ribs/cartilage due to expansion of the abdomen/ rib cage with pregnancy. Other things i think of are gallbladder disease if associated with eating fatty foods, muscle strain if a lot of vomiting in early pregnancy, or gastritis (stomach inflammation from acid).