We are on day 17 with our broody australorp. I candled tonight and all are developing nicely she has one that is a liitle behind either she stole an egg after she started setting or someone climbed into her nest when she got up to eat and drink she was on 7 then all of the sudden 8. Should I fire up the incubator in case she doesnt set on the last egg lond enough? It is about a week behind the others.