I strongly recommend that you go to see your regular doctor
- such as your pediatrician
, or adolescent medicine doctor - as soon as possible. It does sound like this is a persistent discharge, and any persistent vaginal discharge definitely needs to get checked out.
At the top of my list of things to investigate would be ruling out a sexually transmitted infection. Several sexually transmitted infections can lead to persistent vaginal discharge, including chlamydia and gonorrhea. In addition to these sexually transmitted infections, you might also be suffering from a condition called bacterial vaginosis, which is not a sexually transmitted infection per se, but can be associated with sexual intercourse or with other things which change the natural bacterial composition of the vagina, such as douching.
Your doctor will want to perform a vaginal examination, and they may look at the discharge under a microscope to see if this gives them any clues. They also may test you for sexually transmitted infections, which will require either sending a vaginal swab or a urine sample to the laboratory. Fortunately, all of the common causes of this kind of vaginal discharge are easily treated with different prescription medications, but you definitely should not delay any longer before seeing your doctor.