We had a couple of first-years go broody, so we let them sit on some eggs. Unfortunately we are first-years at this as well, so we made some rookie mistakes... like forgetting to write down the day they started! So we aren't sure just how many days they've been incubating, but it's been at least two weeks and maybe closer to three. One of the girls proved unreliable, so we moved six eggs under the other (a Speckled Sussex), and last night we candled. All six appear to have something going on inside: big dark area, with some feathering and some movement visible. Hard to see anything else, mostly just a big darkness. Because the other hens keep jumping in whenever the one broody gets up, we moved her and the eggs into a new box in a separate pen after candling last night. Now I'm worried it may have been after day 18 and we might have damaged them. What exactly is the risk with that? How much longer should we wait? If nothing hatches we're thinking of getting some chicks from the feed store and putting them under her at night.