How dangerous is Bacterial Vaginosis in the first trimester?

Hi. I am 9 weeks pregnant and I had some slight spotting on Sunday, so I went in for an ultrasound on Monday morning. Baby looked great, measuring right on target with a good heartbeat. I went back in yesterday for a pelvic exam and discovered I have bacterial vaginosis. I was prescribed Flagyl for this infection, but my doctor told me that it isn’t recommended in the first trimester because there haven’t been any studies performed on women in the first tri taking this medication. He said if it gets worse to go ahead and take it, but if it isn’t bothering me, to wait until 12 weeks. I am nervous that letting this go “untreated” for 3 more weeks will hurt my baby. Me and my husband tried for 7 months for this little one and we love him/her so much already, I would be devastated if something happened. So my question is… Have you been in this position? If so, what/when did you take the medication? Also, do the risks of getting an infection in my uterus outweight the risks of Flagyl?