Why am i getting such bad pains?

Okay, so i've been burping alot and getting twinges in my belly...also being sick when i burped. i went to the doctors and had 4 blood tests. my bloods came back fine, saying there was nothing to worry about. but recently, ive been burping more. i've felt dizzy, sick, headachy and my pains feel much worse. i've been to the toilet alot, and been to the toilet for a number 2 [disgusting i know] twice a day at least. i drink alot of water and eat properly. does anyone know what could be wrong? no paracetemols or medicanes are helping...also my periods are quite late (i'm a virgin).