Does anybody know why this would happen?

[taraann81]

Hi everyone. I put 10 of my girls eggs in the bator (muscovy). She started sitting ion hers the same day I put mine in the incubator. Same duck, same day starting incubation. I have candled the ones in the bator and see veining. Tonight I saw that she was off her nest which only happens about once every 3 days or so and she is only off for 10 mins max, Today is day 11 for her eggs so I thought I would go in and candle a few. Well I started and candleing ended up candleing 10 whhich is about half the eggs in her nest. They were all clear. Why would this happen? Does it take longer to see veins when they are under a hen as opposed to in the bator? Should I candle the rest and toss all the clears which I think might be all of them or give them a little more time, remember this is day 11 for her. Any advice would be appreciated. Thanks