I've had several abdominal incisions but not a c-section. I felt what could be described as a tugging while each one was in the process of healing. You have several layers of stitches. All of the internal ones are dissolving. Nerves are growing back, skin is attaching to skin and tissue to tissue. You're getting some or more scar tissue. The sensations you're feeling are probably normal but the only one who can say for sure is your doctor. Give him a call.
I've had pain for months after each of my surgeries. The last surgery was for a hysterectomy. My body made lots of scar tissue with each surgery to the point that now, 10 or so years later I cannot run for long or regularly without having some pain. I was also bloated, tho I don't remember my abdomen being firm for weeks after each surgery. My abdomen was tender for a couple of months if not longer. I was off work for 6-8 weeks after each surgery. I think it's normal to not be back to normal at 4 weeks.
My doctors said it's normal to not fully recover for up to a year after major surgery. Any abdominal surgery with a full incision is major. What kind of anesthetic did you have? It does take longer to recover from general anesthetic than local or a saddle block. General anesthesia can add difficulty with memory and focus.