Hi, I Just Notice My Lower Right Rib Is A

Hi, i just notice my lower right rib is a bit bigger than the left. Notice it when i stick out my chest i can see bigger. Even when i try to rub it i feel it bigger than the other side. I had a stomach and pelvic ultrasounds last month because i experience a pain around the stomach area and lower stomach. The result was normal, except my gallbladder has a polyp 2mm. I don't have any more pain since last month. Does it normal one side lower rib bigger than the left? Thank you. Regards, Indri