Do I have appendicitis ?

Yesterday around 8pm, i got a pain in my stomach all over, I thought i was hungry so I went to get some cereal and milk. After eating that, i felt bettter but there was still a small pain coming and going. During the night my stomach hurt a bit, but not enough to stop me from sleeping . I woke up today with real bad back pain . And my stomach hurts too, not speciffacly in one area, but more of everywhere randomley . Im not sure whats wrong, is it appendicitis ? Or is it just back pain cause i slept wrong, or merely a stomach ache .