What Causes An Itchy And Swollen Clitoris?

I am 28 years old, married, female. i have an itchy, swollen clitoris. we just had sex a few days ago. I do not remember having such a swollen clitoris before. A few times i did get itchy clitoris, maybe it was due to some infection, but this time i find that it is very much swollen. when i walk, i can feel it between my legs and it feels like its aroused and erect. Is it due to the sex or due to an infection? I also found that i urinate more frequently than usual, even if i drink little water. i found my underwear moist twice but i cannot say if there was a discharge or it was moist because i was rubbing the clitoris when it was itchy. Thank you. Email: YYYY@YYYY