Frequently we are called upon to replace a gemstone which has fallen out of a piece of jewelry. Often the owner of the piece will mention the they had "felt something was wrong with a prong, and meant to have it checked, " but they just never got around to doing so.
If you find that a prong on a ring, bracelet or other item is catching on your clothing or hair, feels sharp, or simply doesn't seem right, HAVE IT CHECKED.
Prongs wear, bend, and break. All of those conditions can easily and inexpensively be fixed, however a missing gem can be a significant financial and sentimental loss. Don't wear the piece until a jeweler has the opportunity to check it over and tells you it's OK, or makes the necessary repairs.