This is the Bully right? Did you get her to a vet or have you phoned one? She is in labour, right now. Please, if you hav'nt done so, phone the vet and alert them. Do you know the signs of distress in a whelping female? Are you prepared for the whelp, if it goes smoothly? When did you notice the clear sac?
Your vet is definitely wrong, you are unfortunately and unwittingly endangering the dogs life and she needs to be there and get the pups out. As the others have said, please call your vet and do not take NO for an answer.
Misty, congratulations on your babies. I know she whelped 2, lost 1 and then you did a C section with another 3. Yo have 4 doing well as Mommy is. That's wonderful. When you need some help ask and there will be folks to help you.
Good Job and thank you so much for taking your baby girl to the vet and getting the C... hats off to you!!!