He could have been from a puppy mill. Fortunately, yours is a healthy dog. I think that is very important. He did not have a good start in life, but is doing well with you . I got my Suzi when she was 10 weeks. I did not know that 12 weeks is the ideal time for a Yorkie.
It is not a good idea to purchase a puppy from a pet store either. They are often from Large Kennels and mills too.
