Nothing wrong with asking here, but you'll probably get better answers in the actual chicken forums.
(I don't have chickens, so I couldn't tell you much other than what I'd find online)
You can't tell if an egg is fertile by candling unless you incubate it. I know I've said this before. Some shells are dark and hard to see through, so you might not be able to see anything.
Why do you expect activity in an egg that hasn't even started to develop?