So... I have this huge egg from Cass' second clutch that is most definitely fertile, it keeps growing larger all the time. It's probably half the size of a chicken egg... I don't think I'm exaggerating. It is 2 and 1/4" long and 1 and 1/4" wide, circumference of egg taken from width: 3 and 1/4". It's the biggest beardie egg I've seen and completely dwarfs anything that's hatching right now and anything else in the 2nd clutch. It definitely is fertile... think I could have twins? Or am I too hopeful? It's far enough along I don't want to risk candling it to see if I can see two of them in there, but I honestly expected this egg to hatch before anything in the first clutch.