Generally, a vet can tell about half-wayish through the pregnancy if a female is expecting. An x-ray or ultra sound done around day 50 should be able to give you a good esitmate (if not exact count) of how many pups the female is carrying. More importantly, you should be able to tell if the pups are too big for the female to deliver naturally. IMO, a c-section you can plan ahead of time is better than an emergency one, during a troubled whelp, in the middle of the night.
