Antibiotics and pregnancy?

Hi ladies. I had a UTI and took macrobid not quite two weeks ago. Ok no biggie. Well immediately after I now have a bacterial infection (maybe!  I say maybe because I called and described symptoms hoping to be seen and they are calling in a RX and saying its bacterial). 
I'll be 9 weeks on Wednesday. They are giving me two different meds. Flagyl for the bacterial infection, 2 times daily for 7 days, and a single dose of what I'm assuming is a yeast med. I can't remember the name. 
I'm really hesitant. I've read contradicting things online about flagyl and early pregnancy. The CDC says it's safe. Class B. But like I said I've read other things that it's not. Should I be worried? Anyone ever taken it in first trimester and all be ok? I'm already always in a state of worry over the pregnancy. This is really not helping the bad thoughts that I'll lose the baby. Any reassuring or positive advice would really help this nervous mama. Sigh.... ?