I always find that things are "lost" to me when I'm stressed. In this case, the quilting fairies know that if they give the pieces to you now, there might be mistakes and you'll spend even more time you don't have making things right.
Breathe. And remember how much time you're saving not having to do it all twice.
It's worked for me all my life. Except for those disappearing orphan socks from the dryer. That's not the fairies' doing, they told me so :D