I've had regular periods since the age of 11, (I'm 18), and all of a sudden I'm having light bleeding a week and a half after my period! It's stained my panties. My periods are usually heavy and very, very painful but this was random and happening for the first time... I also noticed my vulva changed color, from pink to a darker redish/purplish. Is something wrong? What are the causes of this :X