Hi, thanks for asking.
Sometimes chicks take a longer time to hatch, for example its takes 21 day for an average chick to hatch but the highest time they can go for is 25,
so what I would do is make the slightest hole very very carefully your chick maybe very week but detremaind to live.
here, I'll run you through the steps:
1. go to a warm room and get a very very very slim screw driver.
2. tap the egg very softly and make a peeping noise.
3. then the operation starts slowly break the shell with the tool
4. be very carefull DO NOT POKE THE SCERE DRIVER DEEP if so you will kill the chick.
5. this may take hours but don't lose patients.
6.if you feel like you cant do this then you may want to take the egg to the vets if the heart is still beating under the candle.
7. your chick is too week to come out if its been 28 days and still alive
so help it the best way possible