Did the vet say how far along she is?
You need to read up: Stickies at the top of the Breeders section:
Breeder Talk - YorkieTalk.com Forums - Yorkshire Terrier Community
and check out some of the threads there to give you an idea of what to expect.
And the YT Library: Start at post#4:
http://www.yorkietalk.com/forums/yor...-answered.html
And Breeders Section: Start with this: has list of supplies to have on hand (and take notes):
http://www.yorkietalk.com/forums/bre...irth-help.html
Yes... he could have fathered the litter
I posted a link to this thread there... so hopefully a breeder can help answer any questions.... if no one comes on after a while, PM me.