Those scales look OK to me. Don't worry, I look at mine and wonder if *that* spot was there before, and if it's her or something stuck to her. It's not just you.

Shedding can take awhile. The first thing I tend to notice is my snake gets a little what I call crunchy and will have little sort of flaky looking spots on her tummy. Then a pink tummy, which not all BPs get, then dulling constantly til eyes go blue and back again, then shed a couple days later. It can take more than a week to happen as is. And if this fellow was a little underweight, it might need to fatten up a bit before shed. They're such cute fatties