Not all eggs not hatching?

[chicks2020]

I have started hatching eggs and today is I believe the 25th day. On the 21st day one egg hatched, but we haven't heard anything from the other chicks that were put in at the same time. I'm afraid my one chick might get lonely soon.. and might think about getting some other chicks from the lady who gave me the eggs. I've heard it isn't good to have only one chick. Is it normal for the eggs to hatch on such a long period of time? Are they maybe just duds? Thank you!

 

[Mariachick2020]

You can poke a safety hole and see if you hear piping

 

[chicks2020]

You can poke a safety hole and see if you hear piping

What should I poke it with?

 

[Mariachick2020]

What should I poke it with?

A tooth pick or skewer