Have you spoken to the breeder? If they are a responsible breeder then they will be willing to offer advice and will want to know about the puppies health.
I would be very cautious about getting them vaccinated on Monday - vaccinations should only be given to healthy animals.
It could just be the excitement/change of homes.
I would see what your vet says today, they will probably take it more seriously as the original treatment should have cleared things up.
I would also ask the vet about feeding. Puppies need a good quality food. Don't starve them whatever you do.
How many times a day are you feeding them? Are you giving them any treats etc? People often don't realise that their dogs are eating far more than what is in their bowl!
Also could they be picking up (and eating) anything in your house/garden? Do you have any other animals (like cats etc) that the pups could be nicking food from?