When will I hear peeping?

[Amurr]

So I have 12 eggs in the incubator and am at the very end of day 19. I’ve been having some issues getting my humidity up for hatching and put a damp paper towel in the incubator to increase humidity. As I was placing my paper towel I heard three super loud peeps, but a quick look at my eggs and none appear to have pipped. Is it normal to hear from them this early?
This will be my second hatch and my first hatch with a better quality incubator. My first attempt was a disappointment and a disaster and I’m crazy nervous/excited over these littles!

 

[Mellowmalt]

Tbh, I am not sure, the only thing I can say is my first cuckoo bantam hatched today at 21 days and 20 hours and the first time I heard something was on day 18 but I don't know which egg I was hearing for 3 days before hand.

 

[aroostercalledBrownie]

I know this was a month ago... updates?