It's not just the registration....a reputable registration is just PART of the puppy selection process. The reputation of the breeder, the quality of the breeding parents, the health testing done on the parents and the lines they are from are all part of choosing a purebred puppy. To not follow the basic parts is gambling with the puppy's purity and health, and possibly supporting a byb or puppymill.
That being said, I understand that, for most, once you have your puppy, he's yours and you love him no matter what. So, love on him, give him good food, quality medical care and a great home and he'll love you for life
Congratulations on your new puppy! I'm guessing his name is Tucker?