Assist hatch?

[Deca]

So - have 4 eggs in the incubator, 2 bantam Polish & 2 bantam Silkie. Candled as supposed during the 21 days and all look well. Day 19 both Polish hatched. Now we are at the end of day 21, but still no external pips in the silkie eggs!? Haven't checked for internal pip yet as we do not want to disturb too early, but we do want to start assisting timely....what to do?

Thank you!

 

[Pyxis]

If you want, you can candle and see if they have internally pipped, it won't hurt anything.