C-section pain 11 months pp

On the 5th I will be 11 months pp. I had a c-section and it was terrible. My OB said she made my stitches extra tight (I don’t know if that has anything to do with the problems I’ve been having). I will have pain in my incision area on and off. I have started working out again and trying to be gentle. But I have started having a lot of pain tonight. I had to stop my core work during my workout because I felt, at first, a pulling feeling and now it’s just painful for me to move in certain ways. Any use of my core is painful. I don’t feel like I did anything wrong while working out. Is this normal considering I haven’t done any kind of real core work since before I got pregnant? Should I get looked at?