My nipples are very sore, and i have a brown discharge from my vagina. took plan b a week ago, should have my period in two weeks. preg test negative?

Plan B: The Plan B pill works by altering hormonal levels in your body, and thus preventing a pregnancy. These same hormonal alterations can possibly cause soreness in the nipples and abnormal discharge/bleeding. The preg. tests are sensitive, so negative is a sign you are most likely not pregnant. If the discharge persists, be sure to get evaluated, as you could always have an infection as well.