Some of mine in my first hatch took up to 24 hours from pip to zip
Is the one that looks to be pipping in the small end sitting in an egg carton or is it lying on its side? (is this what you mean by upside down? pictures really help)
If it is lying on it's side and the chick has started to pip it should be ok.
If you have to move it to be on it's side, you might want to wait for someone more experienced to chime in with advice.
If it was me, I would take that egg out of a carton and lie it on it's side to give the chick a chance to hatch from the small end. If it is just that you had it upside down in the carton and the chick has oriented itself up but that is the small end.....
My only concern is where is the aircell
but if the chick has pipped it can breath from air outside the shell
Hope that makes sense
At least this will give you a bump and keep you on the top.
good luck