Our little guy is 16 weeks old. we got him at 13 weeks and the first two nights he slept straight through the night from about 11PM-8AM. However, now his new thing is to get up around 3:30 to go potty. I am pretty sure he's doing it just to get out of his crate but didn't want to take the chance and have him have an accident. He does go pee and poop each time. However, after reading this I think I am going to start taking his food away two hours before bed and see if he can make it through the night! 
 
This site has such great info for newbies to yorkies like myself!! It's so great that everyone is so helpful and understanding