For years I took bitches to be mated twice, between days 11 and 14, but never really after that. Mostly they got pregnant, but not always. I never progesterone tested or scanned, just got on with it, but with progressing science things can only get better. Without testing, Kaiah would never have got pregnant, she ovulated on day 20 or 21.
In the photo we have Asha with her 7 bitches and 2 dogs. She was one of the first I had tested in 2011, at the time it was an in-house vet test, similar to cytology. There is now better understanding of this test, but unless I used it in conjunction with progesterone testing, then I wouldn't use it. "Vaginal cytology is performed on female dogs during their oestrus cycle to help determine the optimum time to breed and enhance the success of pregnancy"
Progesterone testing gives us the day of ovulation, we can then calculate that puppies will be born within a three-day time period. Calculating from time of mating is nowhere near as accurate as puppies are born 63 days, plus or minus a day from ovulation and not mating. With sperm living for days a successful mating could happen days before, or after ovulation. For me, getting this "due date" is even more valuable than getting the day of mating smack bang on.
Then there's the scanning, I didn't do that either. It used to be said that bitches "upset" at the scan could lose puppies in the litter, it was too great a risk to take. Of course now we know that early scanning shows puppies that may not be viable anyway, scanning after 33 days gives a more accurate count. Most people performing the scan will only give a baseline ... but knowing if you have 3 or 6 puppies coming, for example is important. If you have a small litter you need to be careful not to overfeed the mother as it may make the puppies too fat for natural birth, if you have a large litter coming then she needs to be allowed to eat what she can manage. Trust me you can't tell from the size of the bitch, Ziva was as big carrying 6 as Asha was carrying 9, just a lot more fluid! If she has a singleton, then deciding on an elective caesarian may be the best way forward. Often there is not enough hormonal increase with a singleton to trigger a natural birth. With a progesterone test done at the time of mating and a scan at 5 weeks, there is far more chance of a singleton making it into the world safely!