Burning stretching pain in abdomen area

Hi Ladies! I ended up in the E.R yesterday with the most unconfortable lower abdomin pain. It felt almost like an ovarian cyst pain iv had a couple months back before getting pregnant. All the results came back negative and baby looks great. I was wondering if someone is experiencing pain like this. Its hard to explain but all of a sudden i get this burning stretching pain that moves across my stomach. My body is also very small and Iv been the same weight since I was a teen. So im wondering if its my stomach stretching. Im also vomiting and maybe the reflexes from vomiting are hurtingb my muscles some how. Let me kn , and i hope everyone and babies are doing great!!