I've been getting eggs since Oct. 30th. I got one egg with a lot of blood and several with a small spot or two. I am getting fewer of these as my girls' systems get working. I always break one egg at a time into a small bowl just in case.
The old wives tale says its because it is fertile. If you hear that one....it is not true. Just broken blood vessel from mom as the egg is forming usually. It happens once in a while. No big deal and even still safe to eat. If it is too noticeable, my dogs have a scrambled egg treat that morning