Female; 21; sharp pain in nipples, not breasts just nipples. Also no period in 5 months? No pregnancy, not on birth control, not sexually active.

See your doctor... Your symptoms warrant an evaluation by your physician. They would confirm that you are not pregnant (if you have never been sexually active that is an obvious however, in your information you have pregnancy documented as "doesn't know" so it sounds like maybe you think it may be possible? In addition, hormone levels would likely be tested to see if underlying cause for cycle abnormalities.