It is safe to eat if you want to, and you do not have to worry about the hen that laid it.
Eggs that are sold in the store get candled to check for blood spots, because people usually do not like to find blood in eggs. (I think the ones with blood spots go to places like bakeries, so they don't get wasted. No-one will ever notice if they are baked into a cake!)
Blood spots are from a blood vessel breaking when ova is released from follicle.
Meat spots are from a tiny piece of tissue breaking loose from the reproductive tract.
One hen of mine consistently lays eggs with blood spots or meat spots in them. She is perfectly healthy, you have nothing to worry about with your hen!