[Quadraphinic]

If she hasn't pooped by the time your vet's office is open, I'd give them a call, and ask the vet what they want you to do. You'll get great advice here, but anything that can put your Yorkie at risk, I'd always call the vet. Please let us know what the vet says or if she starts going on her own, we like to hear the results when people ask these kinds of questions, and want to know if your puppy is alright.
Cheers Quad