It might be coming from your nose because that's my problem. I'm 13 years old and a female in eighth grade going through this. It's called sinusitis or post Nasel drip. Everyone at school does the same thing to me and makes smart remarks. My parents sniffle or rub their nose but they say they don't smell anything. My dad had the same problem but for some reason it's gone for him. This problem has even made me want to stay by myself and my parents ask me why am I acting weird. They act like nothing is wrong but when people walk by me or near me they run their nose or move somewhere else. I have tried them taking me to the ent doctor but they won't and. I have to suffer everyday with this. Going to school is the worst part even playing sports on a team. I have even heard my coaches talk about it or make fun of me and even run or cover their nose around me. I have missed so many days of school because I can't go anywhere without peace.