A pit bull pregnancy lasts about 63 days, but it can take anywhere from 58 to 71 days. A pit bull pregnancy that lasts 72 days or more is not normal, thus a veterinarian usually induces labor.
Signs of pregnancy occur about three weeks into pregnancy, with possible nausea and loss of appetite. At that point, a veterinarian can confirm the pregnancy with an ultrasound. A veterinarian can also confirm pregnancy with a blood test around 30 days after the female pit bull is bred. At about 45 days, the puppies can be counted using a radiograph. Female dogs typically don't need assistance delivery puppies.
Beginning at approximately 45 days into the pregnancy, the mammary glands become swollen and filled with milk prior to the birthing of the puppies.