I am 21, 5'2 and weigh 95 lbs. Before I began feeling these symptoms I weighed 105 lbs. I have a burning pain in stomach and chest, and feel nauseated, sometimes vomit acid after eating. I also have a loss of appetite. My D.O. diagnosed me with GERD. Lately I have been feeling movement in my lower abdomen, on the left side only. It feels like something inside my body is pushing against my skin, similar to gas. I also have pain if I feel any pressure against my lower abdomen. I took a pregnancy test and it was negative.