Could you tell me abut yeast infections?

I'm 6 months pregnant and for a week, I've noticed itching, burning, irritation from my . I noticed today there's yellow pus bubbles? I asked my mom what it is and she said probably yeast infection. She said you can get it during pregnancy. It's not always a ually transmitted disease. Also, I've had with my boyfriend before I even considered this, so could he have it now?