hatching quai eggs is not a rocket science ! they're easiest eggs to hatch, just be patient and a little luck, most of the time eggs don't hatch the way we wanted because of the incubator's temp is not stable, think about how quail hatch in nature ! with extreme weather they still hatch for...
20 days is too long, i don't think they're gonna hatch. just remeber next time try to monitor your temperture, make sure they're as close to 100 degree f as posible, pour some water under incubator tray and that's it ! remember if u used the auto turner ensure u place the eggs small end down...