I hope you don't find this strange... can I give you a call even though you don't know me... sorry I just need to talk to someone about my questions. Thanks!
If your incubator was running a little cool, it could take the eggs a bit longer to hatch. Most people advise to keep your hands off the incubator, every time you open it you lose humidity. Some breeds hatch earlier than average, some a couple days later. Try not to panic.
X2 on the cool temps in the incubator. If you are running a bit low on temp, the babies develop slower. So the hatch is delayed a few days. Make sure your humidity is up around 70%. You can open the lid of the incubator if you don't see any pips. But if you see ANY pips, you should NOT open the lid unless it is an emergency as this will dry the chicks out, causing them to stick to the shells. You can add damp sponges to the incubator to get your humidity up if you can't get it up with the water in the bator alone.