It can also depend on how well it has been preserved. If it has been stored properly, and the ham is salted enough, it should last up to about a week.
Besides you can tell when a ham has gone south. If it turns brownish or greenish, there is some slimy substance on the surface, or smells funny, it is a no brainer.
If the colour is healthy, the texture and the smell is healthy as well, I wouldn't worry about it.