An idea of what's going on in the eggs today
I found this and it's a great example of what's happening in the egg at day 18. Ignore "needle punch"
Idk about you but my eggs don't have needle holes in them. But, anyways

I still see veins. If you see veins in candling they still have quite a bit of time left.
All the blood that's in the veins in the eggs, needs to go into their bodies. If it doesn't they die.
They absorb all the yolk and all the blood and then hatch.
I think I may have seen one poking its beak into the air cell but god who even knows what's happening in those eggs.
Day 19 or 20 the amniotic fluid will be gone.
Depending on the chicken and what it feels like doing because from what I've seen, some seem more ready than others.
Mr wiggles is not having the egg thing for much longer. I'll give him until day 20, bet.
Actually some of my eggs have had needle punches. I call it a safety hole.
When I see them internally pip I give them a day to break the shell. Eventually they run out of air from the air cell and if they don't break the shell they suffocate. So I help them cheat death by poking a hole in the top of the air cell to allow them to breathe and gain the strength to hatch.
I did that with almost all of my turkeys.
That turkey story is an interesting one.
Achieve your health goals from period to parenting.