Gestation (pregnancy) in dogs lasts 63-66 days. At 5 weeks (35 days) most dogs will start to have abdominal enlargement but should not be producing milk yet. At this point ultrasound is the most reliable and accurate method of pregnancy diagnosis. Fetal skeletons calcify at day 45 and can be seen on x-ray; this is the best way to estimate the number of puppies.
If you have any concerns about your dog have her examined by your veterinarian; your veterinarian can also help make sure you are giving appropriate pre-natal care.
If you have any concerns about your dog have her examined by your veterinarian; your veterinarian can also help make sure you are giving appropriate pre-natal care.