I just had a chick that pipped and didn't start zipping for almost 32 hours. Go for a walk. Go to the Store. Do something and that is when the action will happen. Some of my chicks started hatching 2 days ago on Day 19. There was so much action in my bator the last two days and now that it is Day 21 and I only have 1 pipping with a few eggs left that show no signs.