A delicacy in the Philippines, they usually use duck eggs commercially, but often use chicken eggs at home. I never could eat one, but did at least try. The middle is like chicken soup. That part I could handle.
When I was in the Philippines I learned that earthquakes will cause the embryo to stop developing, so to avoid wasting fertilized eggs that were partially developed they boil and eat them. Yes it's gross for us Americans, but it shows that you have nothing to fear from eating a fertilized egg...