
The thing about the premate test is that the Vet may say mate within 48 hours as many bitches will stand at or just before ovulation, but actually you have up to about 4 day from ovulation to effect a mating. The eggs are unripe when ovulated and are incapable of being fertilised until two days after ovulation,a nd then remain viable for about another two days.
so if your bitches ovulation is only imminent she may not ovulate for another day or so, and still be fertile for another 4 days after that.
Many stud dogs choose not to mate a bitch until she is really ripe, some bitches won't stand either, but those who have had previous litters often are keen to stand earlier than needed.
Most of my successful matings have occurred when the bitches are very ripe and almost going over, and this is why they nearly always whelp at several days under the 63 days.
When vets advise mating they are going on the perceived average, mating just before or around ovulation day, which traditionally was days 10 to 12 as the average bitch ovulated day 10 to 12.
I sympathise over the maiden dog situation, but patience is the key, if not this time then next time. I am considering using maiden dog and it is more of a risk, but every dog has to have a first bitch, and with an experienced girl encouraging him he will no doubt get there in the end.
I wouldn't begin to panic until at least 4 days from the premate test, and even then it was imminent and not showing that she was already ouvlating.