machinfarm
Chirping
Depending on the age of the egg, there might not be a huge air sac. Not to sound like you don't know what you are doing but just to be sure, are you candling the large end? Are they shipped eggs?
This is how 16 of the 24 look, half dark half light. The one with visible veining looks like this but with veins. I can make out a small darker circle within the dark shadowy area, I have no idea what I'm looking at. ive looked At lots of candling pictures and can't really find ones that look like this.