I consulted my doctor about pains under my right rib and he said it was nothing serious but now i'm starting to experience pains on my left rib.help?

Thoughts: Your doc had the benefit of a history and exam, so at that point they had much more to go on than provided in your post. Consider that the large intestines crosses right to left just under your rib cage. Retained gas when it collects in a pocket will overstretch the area of the bowel & cause pain. If gas,laying with your pelvis higher than your chest may help it move & exit.