How do i know if i've had an allergic reaction in my vagina?

Hard to say but: It really depends on what your symptoms are.....Such as redness itching ..Maybe mild swelling ..But not usually a white discharge or fever.Or painful swelling...An allergic reaction might be due to a new soap , vaginal cleansing product , condom etc. , ...Best to see our gynecologist ..And then if necessary they can send you to an allergist. Good luck.