Golden Retriever and False pregnancy

Question
I have a 3 year old Golden Retriever who I bred in March.  It is now Day 64 and although the family I left her with for 5 days from day 9 to day 13 after the first red show I noticed.  They didn't see them tie up but felt they may have since they were together alot during those days.  THe male has successfully bred before.  I just took her to the vet since I was concerned, not being able to palpate any pups.  She has gained weight in the chest area (but not dropped into the abdominal area) and has milk (if expressed by me).  We are ready for puppies but it appears to the vet that she is having a false pregnancy.  My question is how often after a false pregnancy is a successful breeding achieved.  He encouraged only one for try at the next heat and then spaying. Any more advice?

Answer
I doubt they bred. Never leave dogs alone and assume they have achieved a tie. They should only be put together morning and evening beginning on the thirteenth day until they DO achieve a tie under supervision. And then every other day if you choose to repeat the breeding. USually once is enough.
Dogs left alone can injure each other or themselves if they DO tie , especially if one is a beginner. And, as you have now discovered, often don't tie at all. FEmales can injure a male QUICKLY and easily when they are not experienced females.
Leaving the dogs together encourages frustration and injury.
If want to insure a pregnancy have cycstology and hormone levels tested beginning on about her twelfth day via vet exam and they will be able to tell you the optimal day for breeding.
There is a possiblity that she was pregnant and absorbed the pups but doesn't sound like it. You should achieve a pregnancy if you follow my advice, false pregnancy or not,. If the dogs are healthy and capable.
Cindi