When is early, too early?

[onehorse]

Today is day 21, but I can't remember if I set these eggs in the morning or the evening. But, I had a handful pip yesterday, Day 20, and had 2 hatch overnight. I now have 16 chicks in the drying stage and over half of what is left to hatch has pipped and are talking. But the last two hatches that I did out of this incubator were within 2 hours of 21 days from set to first hatch. Temperature and humidity were kept about the same for all 3 hatches, but this one was definitely earlier, but I am not sure if it was too early and I need to adjust temperature and such? Do incubators break-in over time?

 

[ChickFila]

I would not touch anything until all chicks are hatched.
Once I tried to adjust the temp. during lockdown and it made a huge spike!
Just wait patiently... If chicks are hatching ok, just wait... wait....