BV keeps returning! 12 weeks pregnant!

Tash
Please only serious answers! I have had BV 3 times within the past two months! It keeps coming back and my OB is not giving me a reason on why it keeps returning! They just prescribe me metronidazole and send me on my way 😢 has this happened to anyone else?! I am scared that this is hurting my baby. And will me taking all these antibiotics harm my little one??? Please I'm stressing out!