My stomach have been swollen for two months, and i recently started getting headaches and gum bleeding.

Different Issues: You'll need to see a dentist for your irritated gums, and your PCP for all else.

3 separate condition: You have 3 separate problems that need to be addressed separately. 1. Stomach problems and headache see your PCP. Bleeding gums, see a dentist. To receive the best care, you should always first consult your primary care physician, and he/she might refer you to a proper specialist for each problem.