The gestation period for dogs is 63 days or 9 weeks. Is your dog pregnant already or are you thinking of breeding her? What breed of dog is she? How old is she? If she is already pregnant, what breed of dog is she bred to?
If she is not already pregnant, PLEASE don't breed her until you have some knowledge of dog breeding. It can be very dangerous for both the mother and the puppies if you don't know what you are doing, and dog breeding isn't something that you learn by doing. There are too many things that can go wrong that you can't plan for, not to mention that before a dog is bred, they should undergo a full set of genetic tests to make sure there are no problems present that they can pass along to the puppies. While it's true that many people do not bother to do this before they breed their dogs, dogs from these types of breedings have a MUCH greater chance of ending up in rescues or in shelters where they end up being put to sleep. I'm sure you don't want to contribute to the shelter overpopulation problem.
The safest thing to do is to have your female spayed. If she was accidentally bred and is pregnant now, you can still have her spayed even though she is pregnant as long as she is not more than a few weeks along. The vet will remove the uterus and the puppies and, needless to say, the puppies will not be born, but your dog's life won't be put in danger by making her go through labor either. Spaying her will also eliminate her chances for developing pyometra, which is a life-threatening infection of the uterus. If a dog develops pyometra, there are some things that can be done to cure her without removing the uterus, but these are risky and often do not work, resulting in the uterus needing to be removed anyway to save the life of the dog. Most of the time, this risky treatment is only considered when the dog in question is a champion show dog who has not yet finished its show career and can contribute greatly to its breed by producing puppies. In a normal pet dog, the only treatment usually considered is complete removal of the uterus and all reproductive parts.
By having her spayed you will also greatly lessen her chances of developing cancerous mammary tumors. Having her spayed before her first heat almost completely eliminates this possibility. For each heat cycle she is allowed to go through without spaying her, her chances of developing cancerous mammary tumors grow exponentially. It's such a horrible disease that can be prevented so easily, it's silly not to have the dog spayed.
With the information I have given you, I hope you will consider having her spayed over breeding her or allowing her to have the litter. It really is terribly risky, especially if you have no knowledge of dogs in general beyond the common knowledge of a pet owner or of breeding in particular.
Ghilly
hon, that is easily searched out on the internet. Here is one link that might be helpful.
http://www.petplace.com/dogs/pregnancy-in-dogs/page1.aspx