Not sure whether I would scan again, as I have been told that scanning can cause the bitch to re-absorb,not sure however how true that is. It's an Urban Myth I know a top breeder gets bitch owners to sign to say they won't scan their bitches as they(erroneously)believe the above
If it did the farmers wouldn't scan their sheep & horse breeders wouldn't scan their mares
If it caused termination of pregnancy wouldn't be used on humans either
What they do reveal is the number of bitches who conceive but then reabsorb for whatever reason. Previously they would have been thought of as missing
Most scanners will confirm pregnancy but are reluctant to state how many unless there have been problems before with big/little litters. My friend GSD in Germany had 9 healthy puppies & one stillborn her vet had got the numbers spot on