Pick up a pen light, you can usually get them for about a few dollars. Get a 1/2 ID black rubber hose. Cut it about a inch, as even as possible. Slide it over the light end to make a seal when the light is held to the egg.
In a dark room you do not even have to remove the eggs. Turn on light and hold on large end of egg with air pocket. You should be able to see veins and movement on fertile eggs old enough. This does not work as well on brown eggs then it may be neccassary to make a box candler for those.