[carolina yorkie]

I would try belly bands instead of the diaper. There are a lot of folks on here that make and sell clothing and can custom fit your little one.
Also, keep him confined when he can't be supervised. As young and tiny as he is, he has very little bladder control and will need to learn that the pads are for peeing/poing and not sleeping. X-pens work great. Hopefully, some of the other members with more advice will write in. Good luck.