If you are candling brown eggs, they can be very difficult to see though! Try taking a fresh egg of the same color, and compare to that. The developing eggs should be darker, harder to see though. If that is what you see, let momma do her thing. I could not see any veining with my brown eggs.SO frustrating being ignorant and not good at much(sorry-am VERY frustrated-grrrrr) BREATHE-just tried to candle eggs and can't tell ANYTHING for sure. Its day 11 and altho there were differences in eggs NONE of them had veins that I could tell. MOST of the eggs(only candled 7 of the appx. 12 eggs under her) seemed predominantly dark with the "air sack" at end clear. didn't look like a chic form -TOO much dark it seemed to me. and the others that were different looked simalar to the ones I have seen online that showed POSSIBLE bacterial growth(but not definitly so you don't want to toss them IN CASE) I am blue. ANYHOW -in frustration put ALL eggs back under her and came in almost in tears. And am going to try to look up more pics. dumb chickens.(not serious but am SO frustrated)
