there's this thing to tell if a bird is alive in an egg by putting a flashlight on it you can see what's in the egg. I tried it on a robins egg because the mom was next to the best dead.. And I see the yolk in the egg.. Is it alive and still growing or is it dead???
That robin's egg is not fertilized then. I don't want to have to explain the birds and the bees to you, but if it's a yolk and not an embryo, then it never was living in the first place.