Do not use potty pads unless absolutely necessary. Potty pads will inhibit potty training. It is confusing for them because it feels like a thin carpet, so they can’t tell the difference between going potty on the pad or on your carpet/rugs. If you have to be gone longer than they can hold it then use a litter tray with litter (alfalfa pellets-they smell like grass which reinforces going on grass), or even a small piece of sod/real grass placed in a shallow pan. There are companies that actually deliver grass patches to your house. Rule of thumb is that a puppy can hold it for one hour longer than their age in months. I.E. if a puppy is two months old then they can hold it for three hours, if they are three months old then they can hold it for four hours etc. (given of course they have been to the bathroom before being in their crate/playpen) This rule only applies for during the day. During the night they can hold it much longer because their bladder becomes inactive just like human bladders do. Taking away water and food a couple hours before bed helps them hold it longer through the night.