Hatching question

[SunBaked]

Just wondering how long before the peachick in the egg breaks the inner membrane and pips the shell. I have a peachick that's been peeping away inside the shell all morning but still no pip. Will it run out of air soon if it can't manage to pip? I've had one or 2 chicks that had their head stuck under their wing and needed help out of the egg. Worried their is a similar problem with this one.

 

[SunBaked]

Whew never mind he finally pipped. I was starting to worry, never had one peeping that long before pip.