The numbness can be from the damaged nerves from your c-section healing. It can take up to a year or longer (this is what happened to my friend).
For myself, when I was pregnant with my son - he sat against some nerve that made the top right part of my thigh numb to the touch... it didn't go away for about 4 months afterwards. Of course I was 270 at the time of his birth, so the weight combined with the pressure of my little guy sitting against some nerve.
If you are concerned - a doctors visit can always help
Congrats!