Itchy vulva

I'm almost 6 months pregnant and every once in a while I'll get this uncomfortable itchy feeling on just the what I guess would be the labia minora, I don't think it's from a yeast infection, as I haven't had any swelling or abnormal discharge. It is a little red and it usually only lasts a day or two and then it's gone for a few weeks then does it again. I'm a little embarrassed to talk to my doctor about it.