Very itchy labia, huge swelling

woke up this morning and was very itchy. when i went to the washroom i noticed my right labia is as swollen as it could be! ive went to my doctor for pap recently and im clear dont have to go back for a year. ive been living with my boyfriend for 2 years, no change in partner for over 3 years. my vagina has been itchy for afew days but that has happened before! whats going on with me?