Okay it is day 21. The night of day 21, actually. Out of my 17 eggs that were healthy looking at day 16, not one has hatched or even looks like it wants to hatch. I am sure nervous since I am doing this in a kinder classroom. What do you think I should do? Or, I guess the question is, how long should I wait? I sure don't want any exploding eggs, but don't want to hurt a healthy late bloomer either. Help!!!