If you're pain isn't better or its worse, dial 911. You could die if you've got advanced appendicitis
Could you be pregnant or have your appendix still? Is it on the right lower part of your lower belly. Is there any fever, vomiting? Are you sexually active and have you missed your period? It could be a tubal pregnancy. You really need to go to the ER if it doesn't subside. Or could it be gas, is it traveling pain? Have you taken anything for the pain yet? Gas pills, Tylenol, Advil, anything at all?