swollen and painful under your arms could be a sign of an infection. Go to the doc and get checked for vaginitis, gonorrhea, and chlamydia--oh, and have a pap done.
Underarm pain, like what? Just general hurting under the arms, is there swelling, lumps, any sort of skin irritation? Is it over the area where you have hair /shave your underarms or is it more to the front or back (side of your breast area?)