day 22: Help with chick that hasn't pipped and isn't moving

[Jeni11]

My bantam silkie hen has been incubating her egg for the past 22 days and it still has not pipped. This is my first experience with any type of incubation and hatching, so I'm educated to the process but still a newbie. I have candled on days 7,14, and 18, from what I observed the chick was developing normally. Between day 19 and day 22 she has gotten off the nest for about 30-45 minutes, which I thought she wasn't suppose to do. Because of this, I candled yesterday (day 21) to make sure the chick was still alive, but I worried because the chick takes up less space then the air cell. Is that common with silkies?
When I candled it the chick was moving and I'm pretty sure it looked to be in the right position for pipping. She got off the nest this morning in a frenzy when I went up to feed my other chickens breakfast. I thought maybe there was something wrong with the egg, so I took it inside to candle it. When I did, there was no movement or chirping. I then proceeded to do the float test. When I did, I would say that the egg was 10-15% above the water's surface at about a 15 degree angle. From what I've read the egg is viable but I'm confused because it is not moving. It is back under it mama, but what does this all mean and what are the next steps that I should take? Any help would be greatly appreciated as this is the only chick out of the 4 others that successfully developed.

 

[loveourbirds]

if the chick hasn't hatched by day 23 its probably a loss. even if the chick did develop, it may not have an egg tooth to pip with. this can be hereditary. it could have also gotten jolted to much. it may have gotten to dry, or to damp. the air sack does seem large from your description, was the egg older or had it been washed?

use caution handling this egg, it may explode.