What could this be....??? A little worried!?

I'm 15 weeks pregnant and it seems like since i've found out i've been getting what I believe to be yeast infections.. Every time I have sex with my boyfriend I get extremely irritated around the top part of my vagina... TMI sorry but yea... My pap from my prenatal visit came back and everything was normal.. Would a yeast infection even show up in your pap results? I dnt understand why I would get so itchy down there when I dnt have anything... I'm going to let my doc know at my next visit but I just thought i'd get some answers here too... Ne one else had problems with yeast infections?