If you are having a positive pregnancy test then you are pregnant or were pregnant. There is a chance of a chemical pregnancy which is kindof like a really early M/C and that can account for a positive test and then a few days later a negative test. Brown discharge and even slight bleeding is not unusual in early pregnancy. What you want to be concerned about is heavy bleeding, passing clots and severe cramping. I am not sure how your Dr. does not know if you are pregnant or not, did they give you a test? Some women will have an early test reading, because some women have higher levels of HCG then others especially if you have a short cycle, less then 28 days. I would take another test and possibly go to a new Dr.
im concerned about the brown discharge cz earlier there was little brown discharge bt after i gone to doctor it increases with pain and bleeding bt this bleeding is slight and my discharge is without any smell or itching. my doctor keep me on medicine for week and then she will do my blood test and ultrasound. im very tensed cz this is my first pregnancy and i dnt wnat any complication. or is there is anythng wrong wid my uterus.. i also notice that whenever i take medicine my pain in back n abdominal increases and brown redish discharge cuming.