Itchy before getting my period

Hi! So for the past 2 months my vagina has been feeling really itchy and dry a few days before I get my period. I also produce a lot of white thick creamy discharge. It's still fairly itchy throughout the entire month but it's awful before my period. I've been on the nuvaring for 8-9 months now and I've never had any problem. I took something for a yeast infection, nothing. Anyone has an idea of what it could be?