Vagina infection

HI mummy, I received a call from KKH on being positive for Gardnerella Vaginalis (after having brown discharge and done a vaginal swab and was also prescribed with Utrogesta). When I went down to the clinic, The doctor answer was like very vague , he said this is common and has no impact to the baby and even after eating, it will not be 100% cured, I can still be positive for GV. If the brown discharge is bothering me , I can eat the pills. Then, what's the point of eating anti biotic? I am just afraid it will harm the baby.