It's an antibiotic. It has a wide range of uses. Why did the dr say he or she was prescribing it to you?
Trich and bacterial vaginosis is 2 that I know of.
I had an STI called trichamoniasis.
They gave me the drug in a high dose (4 pills at once) at 14wks.
I will PM you the rest of the details as I don't want to scare anyone else reading this.