What Does Random Itchy Bites On Vagina Mean?

I don't know if it's because of a whole lot of stress ive had lately but i have random "bites" all the time and i dont think its because i get bitten it'll come up randomly and never only one bump its itchy just like a mosquito bite and as well my vagina doesnt itch through the day but if its been for then 5 hours sometimes or more it gets extremely itchy. i've ben checked for stds and such a while back and i haven't had intercourse for over six months. could this all be due to stress?