This post is so helpful! I've received tons of misinformation regarding how to tell if an egg is fertilized. For starters, I was frustrated when I tried candling my eggs, not aware that an egg must be incubated before candling will work. One of my hens is laying once a day now and one of the eggs was cracked so I decided to check out the yolk, having been told that blood spots will indicate a fertile egg. Wrong again! I am pretty sure the egg was fertile now, as I studied the white spot a bit. Anyhow, it's great information to know!