@nikkicxncel lie down, press firmly down into the lower right side of your stomach (just above your right groin) with the four fingers of your right hand and let go quickly. If that hurts it’s a sign you could have appendicitis. Go back to ER and tell them to check you for appendicitis! If they they insist there is nothing wrong, go to another ER and insist on checking you for appendicitis! If the second ER doctor still can’t find anything wrong with you, ask him/her to get you an appointment with a gastroenterologist (GI) as soon as possible.
Do you live with your parents, or are they living near you? Could you get one of them to go with you and talk to the ER doctor?