DAY 4- When candled, what should I see?

[Crickett]

I put my BB eggs in the incubator on the 18th. When I candled two of the eggs, I could see the yolks and the air sac. Is this what I'm supposed to see? I didn't see any veins or anything. Is that normal, or are my eggs duds?

 

[Crickett]

Boy! Don't I feel dumb! I just read the sticky on candleing eggs, and it's answered my questions. I'll candle again on day eight and see what developes. Thanks for the stickys!