Bleeding. What are you talking about? Your period? I'm not sure that is related to the flu. But, here is something to check. Sounds gross but it happens. Could you have left a tampon in? Check to make sure. There is a reason why I'm asking this. being sick can throw off our hormones otherwise and brownish blood is old blood. Coughing can bring that out. so, I don't think this is an emergency or anything. Call your doctor though if you are concerned. Hope you are feeling better by now!