However, there are a few things to keep in mind:
* Gestation length can vary slightly: Some breeds may have slightly longer or shorter gestation periods.
* Pregnancy can be calculated from the day of ovulation: This is not always the same as the day of mating, so the actual length of pregnancy can be a bit off from the standard 63 days.
It's important to consult with a veterinarian for accurate information regarding an individual dog's pregnancy.