I'm so confused! I've been reading posts and webpages about candling eggs, but I feel more confused now than before. I candled my eggs around day 7 or 8 and I have no idea what's going on. Most of my eggs are darker (blue), so I don't know if that's the issue. When will the air sac be present? Is it always there in good eggs? Does it get smaller or larger w/time? I think only one of my lighter eggs had an air sac. I'm going to try again tonight (day 10)...when do I have to worry about bad eggs exploding? Thanks so much!