
Hah - Best practice is really to take mum and puppies to your vet after YOU thinks she's finished, for confirmation that she is empty. He may well x-ray to be sure and/or give her a shot to clear her out. At the same time he should check the puppies for abnormalities you might have missed. That way you are good to go!! You'll have to get somebody to either drive you, or be with the bitch to watch her enroute. Have the puppies in a box on a warm, not hot, pad and covered, by mum so she's not distressed being separated from them. I'd get them 'topped' up before leaving, to keep them quiet!!
I will tell you that one of our bitches had a protracted whelping, in one of my then vet's examination rooms out in Canada (we lived a distance from him and having had to take her in for assistance, he suggested I stay). He lived over the practice so when enough time had gone by with no further arrivals, I could call him down to help with the next one. He didn't want to do a Section. We all came home the following morning and I left hubby watching her and the new litter while I made myself comfortable .... he yelled that there was another puppy coming - my vet had missed it! Clearly she was right in the pelvic area, out of feeling (he didn't bother to x-ray thinking it was all over!!). So an unexpected arrival can happen.