PLace more then one pad down. If you see your pup pee in a certain spot all the time, then be sure to have a pad down. Also, Yorkie won't always use the same pad to poop on where they pee, be prepared for this. I have had three-4 pads down a time. Just make sure you have more then one down on the floor.
AND they are not close to where your puppy eats, drinks.