Congrats on your new addition! He sounds normal, Yorkies like any small dog are notorious for being a little stubborn about potty training - our vet told us that- along with people who've had small dogs, and books too. Of course because they are a terrier breed it adds more stubborness. It's true, there are days when they are great and then it's like the lightbulb turns off. Truthfully Piper was 95% trained by 18 months, the other five percent, what can I say, they're stubborn! Just keep reinforcing the words you use when taking her outside or if you're using indoor pads don't give up just soldier on, eventually the light bulb goes on, they're not your typical dog that catches on after a couple of weeks, of course there are exceptions in every breed.
Enjoy the baby and the kitty cat!