I used to get sharp pains in my upper abdomen, i had my appendix removed after and for awhile it stopped. now it comes and goes, what could it be?

Need an exam: Any unusual abdominal pain, particulary if severe or recurrent, needs to be evaluated. While it may turn out to be nothing serious, pain is the bodies warning system that something may be wrong and should not be ignored. When it comes to abdominal pain don't try to diagnosis yourself. See a physician.

Right lower belly: If pain is still in the area where your appendix is removed a pregnancy, a hernia, an ovarian issue, urinary tract, kidney stone or skin, muscle issue could cause similar pains. Best to get rechecked by your doctor. Good luck.

Gall bladder : curious what your appendix pathology was? Was it necrotic? Classically right upper quadrant pain is more typically gall bladder etiology. However, this is somewhat unusual for a young gal as yourself. Go for an eval with your physician to go through this history and have a physical exam. Have your doc look up the path report. Best of luck!