I have 6 chickens, only 2 have been laying (they are different breeds than the other 4). Yesterday, I went out to collect eggs, and one of the eggs had some blood on it, and it was cracked. I am assuming that the hen that layed it bled, and then she pecked the egg because there was something on it. Is it normal for there to be blood on an egg? This is the first time it has happened. All the hens look healthy and happy. Do I need to be concerned, or does this just sometimes happen? Thanks!