TMI...

I'm 34 weeks pregnant and I have extreme itching on my lady parts. Not my whole vulva, but the very top opening of my lips. I put hydrocortisone on it and it feels like heaven. Anyway, what could it be? I figured if it was a yeast infection it would be in more places than one, but I could be wrong. I have had a lot of discharge lately, could it be from the extra moisture? Any advice on treatment (yes I will still see my doctor, my appointment isn't until Wednesday.) and answers/opinions are welcome as long as they aren't hateful or rude. Thanks!