Sorry about the " Step away from the Bator" remark, it is what we are always told on BYC EZ board when we get to worried about nothing happening in the incubator. I know what you mean, I spend way to much time watching then wondering if it was movement or just my eyes blinking, or did I accidently bump the incubator.
They always seem to hatch for me at night so when you wake up you may see some babies. At any rate, Don't give up and leave the eggs in there for at least 24 days. Low temps early on can cause a delay. These thermometers we get are not always accurate.
Also, I have a Brower Top Hatch and I rarely see movement and peeping is not always a sign either. I don't know why some seem to peep more than others.