swollen and painful stomach

I have been suffering for nearly 3 weeks with a swollen and painful stomach in the centre just below my ribcage. It feels like it's inflamed and burning and this often comes up into my throat. I can see my stomach is bloated and sticking out a lot further than it normally is and it also hurts all over my stomach when I press it. My doctor says it is a stomach bug but as I haven't had any sickness etc i'm not sure how this can be.