My name is Elizabeth and I just started my flock this past weekend with 3 pullets and 1 year old Buff who is currently laying. She has laid 3 eggs so far spaced every 48 hours. I am storing at room temp and have noticed that over time the eggs develop tiny, dark spots that almost resemble grease. Pic shows fresh egg at top, 48 hr egg in middle, and 92 hr egg at bottom. Is air getting in? They are not washed. Is the shell too thin? Thanks in advance and glad to meet you folks!