How long before my chicken eggs hatch after wobbling and cheeping?

Yesterday was day 21 of incubation for our eggs. We woke up and they were wobbling around. I kept close eye on the incubator, anxious to see some sort of progress. By bedtime, they were cheeping from inside the shell. I was hoping that by this morning, I would see signs of pipping, but now it's been about 31 hours of them wobbling and cheeping, with no pipping. This will make day 22. The temperature and humidity have been adequate, I stopped turning at day 18 and the parents are free range, healthy, non-inbred chickens. Any clues as to if I'm doing anything wrong?