I have been having an ongoing brown vaginal discharge for nearly 3 weeks, with no other symptoms (no painful coitus, no itching burning etc etc) ... I am not pregnant, nor do I have any STD's (I am monogamous and get tested annually). However, I was diagnosed with Polycystic Ovarian Syndrome last year, and seemed also to have developed a Bartholin cyst on the left of my mons pubis. Any ideas on what may be the cause?