In theory, chicken eggs hatch after 21 days of incubation. In practice, that can be off by a couple of days due to average incubating temperature, heredity, humidity, size of eggs, how they were stored before incubating, and probably a few other things I can't think of or don't know. So don't get too hung up on hatch being exactly 21 days after you started them.
A lot of times I don't see movement, but I don't generally glue myself to the incubator window. If they are in cartons and supported, I'd think it would be even harder to see them moving. And a lot of time, I don't hear peeping until after one has hatched. Each hatch is different.
You can try tapping on the incubator or try making peeping or clucking noises at them to see if that stimulates them. If it is fairly dark in the incubator, try shining a bright light on the eggs. There are living animals in those eggs and sometimes they react to a stimulus. It is an exciting time and I fully understand you wanting to see something, but it is a good time for patience.
Good luck with the hatch.
