Was there any sign of the wrecked eggs being fertilized. Also, if you hit it with enough light to see through the egg you would have seen a noticable dark spot or veins in the egg if it was fertilized.

I work at a pool and discovered a downed birds nest. The other two eggs were recked but this one was fine, i looked inside it with a flash light but as far as i could tell, it was empty. Im unsure though because there was a sort of shadow going on but for the most part looked empty. Is it too soon for it to be developed and tell? Or is it a dud? The fallen nest looked fresh since there were ants at it and it wasnt there before. Also what kind of egg is it?