Fertile eggs getting pink spots

[chickenchatting]

Can anyone tell me if they ever saw pink spots appear on fertile eggs that are under broody hens. I purchased fertile eggs and they were packaged superbly - no breaks or cracks when delivered. I put them under 2 broody hens and a few days later I noticed pink spots starting to appear on the eggs. They feel rough. I am worried. They are cochin bantam eggs and silkie eggs. Thank you for any insight.