Patient: Hi, im a 17 year old girl and quite worried. Although i worry at every thing, and panic at every single thing. My Urine is a dark yellow/brown colour and smells quite offensive. My periods are always on time. This all started after unprotected sex, which hurt really really bad and necer experienced anything like it..Im now scared to have sex or foreplay with any one in case the smell is too bad however i dont have any symptoms of an std or sti .