I never had BV, but had similar discharge before and gynae said no need to treat unless it bothers me (itch, burning etc). In my case, it was very itchy, so gynae suspected yeast infection and prescribed antifungal pessary to insert, symptoms gone 2 days after. Perhaps you can call the gynae clinic and explain your symptoms? Then if necessary get their clearance to buy meds from GP / pharmacy while waiting for your appointment.