It sounds like the chick is pipping. Your incubator was probably a little cool so it's a couple of days late. It's pretty normal for them to be off a bit. I've even had eggs under a broody be off a couple of days. Things don't always happen exacrtly as they are supposed to.
From what you are saying, it is pipping at the wrong end. Not a thing you can do. If you try to help you will almost certainly kill it. It's got a lot of stuff it needs to do between pip and zip.
Will it die if you leave it alone? Probably not. It's not an ideal situation but its not unheard of either. It happens a whole lot more often than many people would have you believe. A whole lot of those chicks that pip at the wrong end make it.
The best thng you can do is to leave it alone. Anything you do is likely to cause harm. At this stage, nothiong you do is likely to help.
I wish you luck and hope you start seeing more pips. Sounds like you have a late hatch.