If i am now dieting and exercising but it looks like i am gaining weight in my stomach region, why?

Gaining weight: It is common for an individual to lose weight in a non-uniform pattern across the body. So your arms and legs may have responded quicker with more visible weight loss which effectively makes you abdomen seem like it has grown. In actuality, your abdomen may be the same size as before or even slightly smaller, but it just doesn't look like it relative to your arms and legs.