There are countless burn stories that start just like this. They can, and eventually will, find a way to end up under the substrate and lay directly on the glass. My recommendation is to ditch the carpet and instead use only a thin layer of cypress or coconut husk bedding. This will ensure the continued safety of your BP even when you're not around to make sure it's above the carpet where you left it.
EDIT: The cool side temp needs to be looked at separately from the hot spot temp. The purpose of the heat pad is to provide localized belly heat. It is not to raise the temp of the entire enclosure.