Today would be day 21 for the eggs set on the 10th and day 20 for the eggs set on the 11th. Count starts 24 hours after set. Usually if your temps are right you generally start to see action mid day 20. A chick can take 24 hours after the internal pip to make an external pip and it can take another 24 hours from external pip to zip. The zip, however, should be quicker and most zip out in under an hour. Mine usually are zipped in 20 minutes start to finish. If they stall I help.
Do you have still or forced air and have you checked your thermometer for accuracy? I would say it's a tad low for you not having any pips yet going into day 21.
If you are seeing movement that's a great sign and hopefully you'll see some pips soon.