I have a dull pain on the right upper side of my abdomen just under the right rib.i think it appears after eating a little more than normal.any ideas?

Many things: It could be your gall bladder especially if are eating fatty foods, also an ulcer is a possibility. Would recommend seeing a gastroentrologist.

One possibility: Pain in the right upper abdomen after eating may be related to activity of the gall bladder. Inflammation or stones in the gallbladder may cause pain after eating. It's worth having this evaluated by your doctor.