there is no reason you can't keep the pull-up on for nap for awhile longer. Even just put it over their pants. what about putting a towel and garbage bag underneath the child's bedding? If you don't feel comfortable with the child being without yet then I say don't.

I made that mistake once too and it was a disaster. I just started putting the pull-up on over the child's pants until I was sure the child would no longer have any accidents.