@Roberta,
Likely you're all stiff from the rigidity of the surgery?
Or...remember with my disk, I got that whole of body pain thing...? Apparently sometimes your body goes out in sympathy. Also, I imagine your poor brain is a bit swollen, inflamed, insulted and generally discombobulated, which would affect everything.
Was there any specific SORT of pain, or other symptoms, you were told to be concerned about?