I have an Olive Egger that is about 3 years old but I just got her. She has had two eggs...yesterday's was a beautiful olive color (I was so thrilled...my first egg) but todays is olive also but with a blue ring around the smaller part of the egg. Do you know what would cause this? Any advice would be appreciated. I'm new to this. Have 11 other chickens but they aren't old enough for eggs yet.