Has this happened to anyone else???

Ok so for the past two days my stomach all over has been aching. Its not in the inside like an upset stomach but it literally aches. Its mostly at the top towards my rib cage. Im nausic and i dont have a appitite at all. Does anyone know the cause of this and how i can possible prevent the nausea and hurting stomach. I have thought about buying a pregnacy test but im not sure if this is even some symptoms? Is a aching stomach a symptom? My mother in law says quite possibly bc i am so tiny, i only weigh 95 pounds and am 20. If somethings growing inside of me than it could be causing some aches. Any advice ladies? Im desprate to stop the ache.