I'm a sexually active 16 year old girl. The past 4 days I've had an almost constant gotta pee feeling but when I try to go barely anything comes out. I already had my doctor check for a UTI but it's not one. What could this be?? Oh, and the first day my pee was kind of red/pink in color but has been completely normal since then. Could it be an STD or other type of infection...? Please help!