Hi everyone It's my first time incubating and I have duck and guinea fowl eggs set. I know I have a few good duck eggs developing so I am hoping to get at least one to hatch. I am on day 18. Lock down will be next Sunday (duck eggs.. longer hatch time) Tonight when turning the eggs I noticed that one duck egg had a sort of grey and blotchy appearance. Like I could see something dark inside the shell.... or like the shell was going and off sort of colour. This egg is one that I have deemed a 'dud' since my first candling on day 6. At this time I could see a large mass... but no veins. I have never seen any movement or veining in this egg and when I last candled it the mass inside has turned into a horse shoe shape and no action to be seen. When I noticed the shell colour I whipped the egg out to quickly candle it. It looks kind of spotty and gross inside with a mass to one side. The only movement I could see was some of the spotty bits moving.. and that was only if I was moving the egg. I was going to candle once more before lock down and remove any that I could confirm were no good but the fact this has a grey blotchy appearance from outside the shell has me worried. Should I remove this egg now? I don't want to compromise any of the healthy eggs by having one explode. None of the eggs that are developing with happy moving babies inside have this shell colour thing happening!