Most chickens will carry a few worms in their gut particulary if they free-range, unless they have been recently wormed with a proven effective product such as Flubenvet. It is good practice however, to get into a worming regime that suits your birds enviroment.
Saying all that, the worms will be in the birds gut, which you will be removing in the preparation process anyway.
Good luck, nothing tastes better than home reared birds!