Is my stomach too fat?

I am 15, female, 5 ft 7 and about 10 st 5. when i suck my belly in, its usually about 29-31 inches, when i relax, its about 34 and when i push it out really far its about 37-38 inches. when i eat alot then my stomach can extend to about 39 inches and i look heavily pregnant! im moderately active and i eat relatively well, although yesterday i worked out that i ate about 3000 calories and i eat like that quite often, maybe thats why my stomachs so big. i havent got a "fat" belly as such, just a big pot belly and it sticks out quite far. when i stand up strait, relax my stomach and look down i cant see my toes although when i suck it in i can and i look quite skinny when i do. do you think i am fat and is it because i eat too much?