I have had blood specs inside the eggs. Maybe it is disgusting, but if I crack 4 eggs into the bowl and the 4th one has a bloody spot in it, I just pick out the bloody spot and scramble the rest.
My father in law raised egg layers on a large scale (several thousand birds) about 50 years ago. He is gone now, but he once told me that any time there is a stress in the chicken house, you will get some blood spots. He said that this included fighting, predatory threats, or storms. It seems to be true.
Interestingly, his were cage layers, but the cages were huge. The hens had a comfortable environment. He never dreamed back then of using tiny cages. He hand collected the eggs every day. It was a very labor intensive project. He also raised cattle. It was a living, but barely. He got a job offer in town and took it. He sold the hens but kept the cows.