So, I was worried that the air sac in my duck egg wasn't big enough approaching the 28th day, he had not internally pipped yet, so I made an external pip myself to ease my worrying. It is now the 29th day, through the inner membrane I can still see LOTS of veins and they're still a burgundy red, I can still see a fairly large yolk sac, and STILL he hasn't pipped... His blood isn't becoming deoxygenated either and I'm just not seeing ANY progress even though he's CONSTANTLY moving... What's going on? Why won't he absorb his veins and yolk and why isn't his blood deoxygenated yet? Is it going to happen very fast and suddenly? He's a day past due for a duck and he doesn't even look close despite him being healthy and active... This is very frustrating!