Then it smells like an egg, lol... trust me, you can smell a bad egg without getting your nose even close to it... :sick
Might be sleeping, no worries yet... marking the air cell might help, it should tilt drastically when it starts to get into position to hatch and you can see the difference...
Looks like it has developed well and air cell looks good for day 22... I've seen some odd discolorations show up on developing duck eggs, doesn't mean it has died... and if it were rotting or bacteria has gotten theough the shell, a simple sniff will tell you that... no mistaking the smell of a...