Metronidazole gel for bv. Barely any symptom

So I am 28. I have never had bv in my life but one day I noticed a little bit of discharge and a foul odor. (It wasn’t fishy, but it was a strong odor) it was weird. Almost like sweet, but old pineapple. I know it’s gross. But dr said I was positive for bv. I do have a new guy I’ve been seeing and this happened a few days after we had sex. I want to bring it up but I’m nervous. I was prescribed the metro gel for 5 days but I am TERRIFIED from what I’ve been reading. I don’t want side effects. And do I even need it? I just want the odor gone. I’m on day 4 of my period too and don’t know if I should take it. I’m really stressing out if I should start it tonight.