Hmm.. You did the right thing contacting the breeder about it. Do you have a copy of the health guarantee? Some breeders have it posted on their websites. I would think it varies from breeder to breeder. I'm sorry that this is happening to you again! Your vet didn't sound too worried about it, so hopefully your puppy will be just fine. And I'm not a breeder so I have no clue as to what to do there. I do know that it takes quite some time to determine whether or not a dog is breedable.
P.S. I know some of us here love Biewers.. Can you post a picture of your new baby? Pretty please?