Candled my eggs today (day 10) and some I am confident are duds....no air sac visible at all, and dark pool on lower half of egg as it sat in nest. But others had a distinct air pocket on larger end of egg, I couldn't see much above that, but the egg was not translucent. If there is a distinct air pocket, is that an indicator of development? Or do most eggs have an air pocket on one end regardless? Thanks