A dog has a pregnancy of between fifty-eight and sixty-eight days. A little more or a little less could be normal, depending on the breed of dog you have. This is, more or less, two months of pregnancy for a dog. The best way to know if your dog is possibly pregnant is to know their menstruation cycles. (Yeah, yeah, get on me for saying that, but it’s true. Menstruation is a natural part of life, and even non-human species of animals do it.) If a menstruation is late by a couple of weeks, it might be time to get them to a vet to make sure.
However, breed may play a part in pregnancy. This is not confirmed, since dog breeds were inbred to create the “purebreds” we love today.