I recently got a new but factory blemished brinsea eco 20. I set the temp. to 99.5 and put in 4 eggs from my chickens to test it out. I have 15 chickens that have been laying since August/Sept. and 5 roosters, (dont worry we have plans for 3 of them,) and I am pretty sure I have seen the bulls eye in the yokes. Anyway, it's day 8 and 2 of the eggs I can clearly see the yoke and no development, one egg is too blue to see anything, and then this egg has me stumped. I saw no veins, and I didn't at day 4 either, but it's dark in about 3/4 of the shell. I just want to figure out if things are developing so that I can move on and problem solve if they aren't. Sorry for the crumby photos, it was the best I could do.