To keep your Pom from having accidents, limit his freedom in the house. You could crate train. You can umbilical leash him (have him attached to your belt at all times so you can see what he’s doing) or use a confined area such as x-pen with potty pads or some other dog potty to contain and train. Often, little dogs take a while to train and if they have an acceptable indoor place to go it can be easier on you. When you are about to take him outside to go potty, ring the bell yourself on the way outdoors and if he will go on command then ask him to go and praise the heck out of him when he does.