Don't do it.
You need to order a PROOF.
When you are getting ready you can look at the review interface in KDP and it might all look OK but when the proof comes, things might need to be fixed.
I call it The Perfect Proof.
If the proof comes and it looked perfect inside and out on the first try, I will presume the apocalypse is about to begin.
My latest novel proof came on Monday. I had to tune several things. Like the back cover blurb was too far to the left. I had a small detail on the inside as well.
It's also a good time to let your wife read it. She can red-pen it and she'll feel good about it!