Look towards the bottom of the article that says "WINNERS". It gives a description of what you should be able to see in the egg around Day 7. If you click on the link to the pic, you'll see a pic of an egg that has the characteristics of the description. Hope that helps.
hi,
basically in the first couple of days you should see small clusters of veins by day 7-10 you should see a shadow of where the developing chicken is.
i am new to incubating but a lil research go's far lol hope it all turns out for you