Hang in there, the 10 chicks will keep you busy! (My first hatch was 7 of 32 eggs and there could have been one more if only I knew then what I've learned along the way)
Enjoy them -- they grow up quickly.
Don't fret too much over it. Even if it did hatch, it might have been hard for it to catch up to the others. These birds mature fast and they're relentless when it comes to pecking order. For me, this has been one of the hardest lessons about raising quail.