Sure I've found blood on the egg

[tlck9]

I'm sure the last couple if eggs from ind of mh chucks has smeared with blood, looks like the same chuck, not entirh sure which, but what is causing this

[Bramble-Poultry]

sometimes a pin feather around the vent can rupture when laying and put a layer of blood on the egg shell. Othertime (particularly if introducing new birds) an arguement between the birds causing a minor blood shed and it gets on the eggs.

If its a one off i wouldnt worry, but if it is happening day in and day out then use a trap nest to work out which one is the culprit and give her a good looking over.