What could be the reason for a sharp stabbing pain near the incision 11 weeks post partum after a c section?

Probably adhesions: Post op incisional pain such as you are describing is pretty common. It is often difficult to know what exactly the pain is from or even where it is coming from. The tissue at the surgical site is less flexible than before surgery and tends to stretch and even tear a little bit during healing process which can take up to 6 months to complete. My guess is that this pain will resolve in a few days.

Nerves: The C-section is irrelevant. The pain in a wound after surgery can be a problem. Could be a nerve stuck in te scar or a hernia developing. What caused the pain to start? Best to see the surgeon who did the procedure (not a pa or np). This may be nothing but it could be serious. Only your doctor can tell. Good luck.