What Causes Pain In The Right Side Under Ribs?

what causes pain in the right side under the ribs. I do not have a gallbladder and have had a C.T. and a ultrasound done and nothing was found. However, certain foods make my side hurt, I m a female and had a baby, It feels like a babies foot is up in my ribs. I have to adjust the way I set and lean to the left to releive the pain.