What Causes Movement In Abdomen While HPT Is Negative?

am not pregnant but i can feel something moving in the right upper area of my stomach like a chilled i have no stomach pains i feel bloated all the time i feel the movement like three to four times a day its pressing against the wall of my stomach then it fades i have taken pregnancy test and they are negative not pregnant and i have been feeling this movement for the last three weeks can u please tell me what could be the cause thanks.