Candling fertile eggs and how to tell if one isn't going to make it/didn't make it?

[chickmomma03]

No, I didn't take a picture of it. It might not have been. I don't know because I didn't crack it open to find out what went wrong. I guess I'll have to work up the nerve on that one and do that at some point since I'm planning on incubating more eggs. Will it stink if I crack it open, that was my biggest concern with it having sat under the heat.