Has anyone else had oral thrush while pregnant? Especially first trimester?

I had antibiotics last week and, just my luck, now I have thrush. Waiting for a Rx from my doctor, but curious what any of you took.

My research shows the most common med, Nystatin, is Class C ("no idea is it's safe, no firm evidence it's not").

I know I have to take something b/c it's dangerous to let this get worse, but between the antibiotics and taking so much Tylenol for the never ending cold I had, I'm nervous about taking more meds...