Definitely a controversial topic around here...But, I would help. If the membrane is dry it will not be able to get out and will die (so close to being hatched). My personal experience has been that if you wait too long they are really weak from the struggle. If you don't wait long enough the yolk sack will not be absorbed. I would say take the egg out and listen for peeping and movement, check the membrane to see if it is dry, if it is, get a really warm damp washcloth and use it to soften the membrane. Then slowly pick at the shell, to help it zip. Get it open just enough that it is easy for the chick to get out on its own. Then put it back in the incubator and let it finish the process. If there is blood stop immediately...I actually had one bleed quite a bit and I used quick stop (the stuff for dogs nails) to stop the bleeding. Good luck. There is nothing worse than seeing them get this far and then not finish hatching.