If they are going to sedate you for the colposcopy then you definitely need a driver. I always think it's a good idea to take along a friend anyways - for both physical and emotional support. Better to have someone to drive you just in case then to try to drive home in pain. if nothing else you might even get a lunch invite out of it all ( oh sweetie you look stressed - let's go do lunch!!! ).
Take along a regular sanitary pad to wear afterwards. Usually the ones they give you at the clinic are those thick ones that reach from the back of your neck up to above your waist and are 6 inches thick....he he he. Some women have a lot of discharge while others only have a little so err on the side of caution.
best wishes for your procedure