If you only have a male a female yorkie,I dont understand how that could have happened

No,the puppy is not a yorkie.
We´re missing a huge chunk of the story here.How would another male get to her? Did you let her off of her leash and out of your sight? Did you know she was pregnant? I dont know what to say because I dont know what happened and you dont seem to know either which confuses me.When you say "could the father be another dog?",I dont know how that could be,because you havent said so.
I have 2 yorkies,male and female,both intact,and I cannot imagine for the life of me in what case scenario something like that could happen without me knowing about it
First of all,if she was in heat and she ran away (just in case that´s what happened),you should have taken her to the vet once you got her back and had her spayed right away,because unfortunately,when a female in heat runs away,she
ALWAYS comes back pregnant.
With toy breeds you have to be EXTRA careful,because what if the father was a bigger dog? What if he has health issues? Her life wasin danger,and with the pregnancy and birth out of the way,there are now just more mixed pups to find homes for