Stop worrying...snakes shed when they're ready to shed, & not before. It's a process, & there is no exact timetable: basically, they cloud up, then their bodies
secrete a little moisture between the old & new skin, making them "go clear" (appear as if they may have already shed & you missed it, only you didn't), & then
they finally shed the old skin. Be patient, keep the humidity up to help, & don't worry about it.
FYI, one thing that can slow their shed process is if they've been fed recently. That's because digestion requires good hydration, and so does shedding, so if your
snake ends up trying to do both at once, it can slow down the time it takes to go clear & shed, or it can even "mess up the shed" (making the old skin stick & come
off in pieces). Even if that's the case, there's nothing you can do other than provide good humidity & wait.