Did you get a x-ray/ultra sound at day 50? That would of told you how many puppies to expect. Just let her do her thing and she'll let you know if anything is wrong with her or the pups. If she is having contractions for more than 20 minutes and not producing a pup you must get her to the vet. All pups/mum must see a Vet within 24 hours of birth. Good luck, just sit back and watch her for the next 6hrs of birth.