What Causes Swelling In Vagina After Sex?

Hello, there. Why is it after sex my vagina lips are very very very swollen, a little irritated, and yet numb when I touch it. Especially on the left side. This happens immediately after sex, although during the sex everything feels normal. I should mention i am allergic to latex so no condom was used. But this reaction is almost as exact as my latex allergy reaction except not as itchy and burning.