Thanks for the heads up, my medical knowledge of gestation in dogs is embarrassingly lacking.
Neocotez, I highly, highly recommend that your dog gets an emergency spay. If you are seriously interested in breeding Neopolitan Mastiffs down the road then you can always consider it after you have gained more experience and knowledge, not to mention a mentor and dogs who have been proven in the show ring and that have passed all their health clearances (this is more than a check up). Here is some info on the issues that neos are known to have:
http://www.everythingneo.com/index.php?option=com_content&view=article&id=45&Itemid=54
So, for example, since they are susceptible to hip dysplasia a responsible breeder will screen their breeding stock's hips with OFA or Pennhip to make sure the puppies won't end up crippled. Screening is SO important because a lot of dogs don't show symptoms of genetic conditions until later in life, at which point they could have already passed on their genes and produced 20 more puppies with heartbreaking conditions.