Hi, I Have Been Taking Cephalexin For 3 Days. It

Hi, I have been taking Cephalexin for 3 days. It was prescribed to me because I went for my 12 week pregnancy ultrasound and pap smear, and the doctor found some bacteria on the cervix.
In the last day or so, my labia has become very swollen and painful. Could this be the bacteria working its way out of my body? My husband and I also have alot of intercourse at this time. Please advise what you think the symptoms are related to. This has only happened once before when I had a bikini wax and was allergic to the wax used.