One of my ducks has started hatching....4 days early! I noticed around noon yesterday it had piped. Last night around 11 it had partially zipped. This morning it looks the same, and is chirping and trying hard to get out. I'm not sure if it is in the right position or not. Every once in a while a foot comes out of the pip. How long should I let it go before I help? Any advice is much appreciated. This is my first time hatching in an incubator. Here is a pic of how far along the hatch is.