Hi! I am only hatching one egg in a homemade incubator. I saw a slight external pip yesterday at 5pm with some bruising around it and upon candling found that the external pip is about half an inch away from the air sac. At 1pm today I noticed the external pip has a little bit of shell sticking out so I guess the duck has made a little bit of progress. The external pip is on the underside of the egg but not touching the paper towel the egg is resting on. I can see the duck moving some when I shine a flashlight on the egg but haven't seen the egg move or heard any duck sounds. Should I intervene and if so when? I read the helpful guide on this website about how to intervene but I wasn't sure when in this case. It is Day 28. Thanks.