Oh boy, I think we made a newby mistake with our count.
I am hoping all will be OK but we were early with our lock down. We began our count from Day 1, not Day 0. What we thought was the PM of day 18, was actually the PM of Day 17. Easy mistake and honestly, started to get confusing double checking the count, nearly had to take my shoes off after Day 10!
From my understanding, the chicks could be at risk of drowning if the air cells has filled with water due to the higher humidity for the extra day.
Nothing we can do now except wait it out and see. Have also set the eggs with their x's facing up on the mesh, they move quiet easily so hopefully if they start to wiggle while we are not around we will see some evidence if the eggs roll over a bit.