Black egg but nothing is happening

[my monarchs]

I've been watching an egg for about a week now. Inside I can see the wee little critter moving within the egg. At least I think I can: I have a pretty strong magnifying glass. But there has been no change now for nearly a week. Is this normal? What can I do to encourage it to hatch? Put it in the sun, the shade, in the cold, in the heat? Or none of the above?

[Farfalla]

I think the hatching range is 3-8 days? Maybe they are just slow pokes.
But this year I have had one batch of eggs that were taking a long time to hatch....It turned out they were taken over by tiny wasps.
http://www.entomology.wisc.edu/mbcn/kyf104.html
I would keep the eggs in a clear conatiner with a lid with no airholes.
( The hatching cats don't need airholes..and this method will contain any unwelcome visitors.... should that be what's happening.