I'm a 20 year old, thin and active female, but I seem to be constantly thirsty. Could it be Diabetes?

I'm a normal weight, relatively active and have no family history of diabetes. However, I find myself always thirsty and when I do start consuming liquids I end up going to the bathroom frequently. When I'm not chugging back the liquid, I'm normal. I also get leg pains (in the calves or thighs) that could be best described as "growing pains" (in other words, dull achy pain). So what could it possibly be?