I'm having almost the exact same issue. Brewed it Memorial Day around
noon, checked it today and there's no activity at all in airlock, but
man did it erupt over the last two days. Overflowing airlock with
massive amounts of foam. Ferment temp is around 72-73. I checked the
gravity today and I'll check it again on Saturday to see if she's still
fermenting. If not then I'll rack to secondary and leave it for two
weeks. Like most brewers will tell ya, don't rely on the airlock to
determine if it's done or not.....gravity is what counts.