Collecting fertile eggs
Featured Stories on BackYard Chickens
Success rates decline after 10 days, but successful hatching can still occur beyond that point. You can increase success by storing eggs fat side up and replicating "turning" of them by placing them in a carton and elevating the carton at one end to a 45 degree angle (place it on a stack of books, etc) and then changing the end that is elevated 2+ times a day. Store them in a cool room - above refrigerator temperature but the cooler the better around 55 degrees being a commonly quoted temperature.