When can you check if my dog is pregnant after breeding?
Gestation is usually about 63 days, but it depends on the dog. A vet check after day 35 after breeding can usually tell you if she is pregnant or not. An ultrasound can reveal pup after this time as well, but will not normally tell you how many pups there are. An x-ray after day 53 will be able to tell you how many pups to expect, so you know when she is done birthing.
If you know the date of breeding, it's best to just wait until late into the pregnancy to confirm number of pups, as most times, when a dog is bred, they WILL be pregnant, especially if it is not a first litter.