Is the appendix on the left or right?

Right: Right, but it can be long and lay in different areas of the abdomen.

Right lower abdomen: Think of your appendix as a "finger shaped" appendage that hangs off the beginning of your large intestines in the vicinity of your right lower abdomen. One needs to be careful, though in that even though it is located in the right lower abdomen, an acute appendicitis can present with left sided abdominal pain.