I had a bitch with a history of false preg.and uterine infections.When I was intending on breeding her the Vet put her on antibiotics before the breeding took place and did progesterone testing every week till we knew for sure she was pregnant. She had eight. As far as the length of the bitch, they can carry a few up under their rib cage. I helped deliver a litter where the bitch had eight puppies was to the vet got her shot of oxytocin,no x-rays. The next morning she delivered a decayed puppy. The owner ran her back to the vet,but she was already septic and died on the table. We guess there may have been as many as four puppies in her. Have her x-rayed when you think she is done giving birth,if she is pregnant.