I saw the internal pip at 4pm and now it's 9:30 and no pip externally. I'm sure most people don't even know when they internally pip but how will I know if I need to help?
It could be 2 or 3 days until hatch. As long as your humidity is up around 70% you shouldn't need to help. Most times helping does more harm than good. The chick may have pipped- but haven't absorbed the yolk yet, and have vital veins running throughout the shell. Be patient!
It may take a day or two, if your temp & Humidity are set fine you are in good shape. just have some patience, some will pip and quit so be prepared for that. AL