How much walking is TOO much walking?

I've been walking like crazy. I'm hoping if I walk enough at least I might dilate a bit more...then at some miraculous point, Dr. Sanders is going to say, "How 'bout we induce you next week (or tomorrow--this is a fantasy, isn't it?)"

So I keep walking, and hoping, and walking some more until I hurt like I-want-to-be-on-bedrest.