Trying to figure out what just happened...

We did our first grafts while our honeybees were still out in the almond orchards. Eggs were most probably laid on 3/6. We did all grafting on 3/9.

I carefully checked every nuc in the first week of April. Not one queen. I felt sick! Looked a couple of days later, still nothing.

Opened up every nuc yesterday with the plan of installing a frame of brood and a new sealed queen cell.

19/20 of these nucs had sealed brood, eggs, open brood, and a laying queen.

What just happened?

I thought we should have seen the queens by day 12?