Dark when candling?

[goldfishcracker]

This morning i decided to candle my ducks eggs since she had been sitting on them for a long time (im not aware how long exactly but my guess is around 2 weeks), she turned a year old a month ago. We have two drakes as well so I know the eggs are most likely fertilised but when candling a couple of them, all i could see was the air sac, no veins and the light wouldnt shine through the egg. Im not sure what to do or what it means. Also for the rest of them, the light did shine through but i could only see the yolk which was slightly orange/red. Im new to candling and im only using a flashlight, nothing professional so i thought maybe it might be too weak.

please help!

 

[Miss Lydia]

Here is info on what you are seeing when you look at eggs
http://www.metzerfarms.com/Candling.cfm

 

[chickens really]

Leave them..Under Broody Hens I wait till they hatch..Others will tell horror stories of busted eggs and stink...Lol...