Confused?

Okay, this is a strange occurance, but this morning my boyfriend and I had sex, and afterwards my vagina swelled shut and it stayed that was for hours. It has happened once before. I read about it and it gave me a few reasons as to why, however I do not believe I have an infection as taking care of vaginal health is very important to me. I take a cranberry pill daily, eat yogurt often, and and I don't was it with any soaps that could throw off the pH balance. I also didn't have trouble getting wet this morning, and i honestly have no clue about having a semen allergy. Have any of you experienced this, and could anyone give me some tips?