Bad egg?

[Nigellas]

My broody has been sitting on some eggs for about 2 1/2 weeks - the last few days she keeps pushing out one particular egg, the same one each time. Does that mean that one is a dud? I haven't candled, and don't want to this late for fear of disturbing any development.

 

[Gypsy07]

Yes, that egg is very likely a dud. It might even be rotten. I'd take it away right now. If she's not going to sit on it, there's no point leaving it there!

My first ever broody hen kicked out an egg at about 20 days and rolled it right across the coop. When I broke it open it was full of stinking black goop...