Numbing Sensation On Left Side Of Rib Cage Moving To Mid Back Area. Had A C-section. Suggestions ?

hi, I had a c-section Oct. 7th of this year, about a week later I felt what seemed like heartburn , but I;m not sure, went to the hospital had an ekg done everything came back normal. The following day I got this numbing sensation on the left side of my rib cage that wrapped around to my mid back area, and its only getting worse, now I m feeling a sharp burning pain that come and goes. told my obgyn about it, she ordered an xray of my lungs and spine but everything came back negative. and also during my pregnancy I was experiencing alot of constipation. any suggestions would be nice..