21 weeks & contractions

Scariest thing so far! I was having bad cramping and tightening in my upper abdominal to my back. I was nauseous and had alot of discharge. I made an early appointment to see the doctor. She then suggested I go across the street to the hospital. So, I did. Ob triage here I come scared shit less! So they monitor and do different things come to find out I have a bacterial infection (bv) that was causing the contractions. So they put me on metronidazole and told me to take it easy and relax. So here I am laying in bed but feeling better. Anyone have a similar situation? I'm nervous taking the antibiotic but it out weighs preterm birth so I'll do what I gotta. Have you had to be on an antibiotic, what are your thoughts?