I would lock down now and raise humidity (making sure there is still plenty of ventilation as hatching chicks need access to plenty of air). Once they externally pip if the humidity is too low for too long it can increase the possibility of shrink wrap. Most recommend locking down day 18 for chicken eggs as some can hatch early. I personally base when I raise humidity on when I get the first internal pip. You want to have the humidity raised by the time you get external pips if you can.
Good luck with your hatch!