Somehow you believe that this represents a fertilized egg, so the question is usually "do you have a rooster?", to which I answer no. Maybe the fact that you think it's a fertilized egg or rooster spuzzum or something like that makes it worse for you. Would it make it any better to know it's a blood spot?
A blood spot is occasionally found on an egg yolk. Contrary to popular opinion, these tiny spots do not indicate a fertilized egg. Rather, they are caused by the rupture of a blood vessel on the yolk surface during formation of the egg. These eggs are just fine to eat.
The spot can be removed with the tip of a knife, if you must.