You should give those eggs a couple of more days to hatch, because you could have miscounted the days from since when incubation started. Incubation starts when the mother bird has laid all of her eggs, and starts sitting on them regulary. I wouldn't suggest touching the eggs when it's day 21, hatching day. When you candled them did you see a the big black area go into the air cell? That means the egg might hatch. Usually when it's about the day it's suppose to hatch, you can hear peeping. And the eggs can take up to 24 hours to hatch, or maybe even 48 hours. I recommend not to help hatch baby birds. But sometimes people need to help them hatch if the chick is stuck in the egg and needs help. So if you can see the chick like it's beak or face or little bit of its body and no progress is made but you can see it struggling within 24 hours and it doesn't hatch, this a time when you can help it. Gently peel of the shell, and if you see blood you broke the blood veins. Wait for several hours if you see blood before attempting to help it hatch. Good luck!