Why am I having this??

I'm 18 weeks pregnant. I am having itchy feelings in my vagina but no discharge.. About a week ago, I found out I was allergic to the latex in my underwear and it was causing me extremely painful burning and intercourse so I switch but now this itchy stuff? And it's still painful to have sex. Could it be that I'm still irritated from the underwear? Or does it sound like an infection?