yeast infection?

The past few days I have been itchy down there ;( and I read the symptoms of a yeast infection and it sounds pretty similar. The only thing is my discharge is regular and I don't smell anything irregular. I'm thinking that it is my underwear since I have polyester underwear (or something like that) and I've read that cotton is wayyy better to use. Since then I have worn my one pair of cotton underwear for the day and it made a drastic change with itchiness. Can it be something as simple as your underwear causing itchy, or should I look into a yeast infection? I also bought vagisil wash to try tomorrow and see if that helps. P.s. I have huge labia folds that constantly rub against my underwear that might be causing the problem