I had the same problem when i was younger, went docs and they rushed me into hospital, stayed in overnight and felt a bit better in the morning so they said go home, went outside and puked like hell in the car park. I still went home, but i was in bed for like 2 weeks, then it just got better. I think they said it might have been a grumbling appendix, but like what was just said, they basically diagnosed "sort of appendicitis".