It can't internally pip at the wrong end. An internal pip can only be seen when candling. You will see the shadow of a beak inside the air cell, which should be at the fat end of the egg.
Read this. It will let you know exactly what to do and when.
https://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching
Read this. It will let you know exactly what to do and when.
https://www.backyardchickens.com/a/step-by-step-guide-to-assisted-hatching