Tilda, there are some posts on here that can help you with assisting a chick to hatch. Seems that most though, prefer to leave them alone and NOT open the bator no matter what to keep the humidity constant. Whatever you decide, good luck with it. It often takes 24 hours from pip to zip, and the chick sleeps quite a bit during the process. He might pop out tonight while you sleep. If not, sometimes he was weak and not meant to be.
Best of luck on your new chickies, HenZ