A 25-year-old sexually active woman presents to the clinic with complaints of lower abdominal pain, fever, and unusual vaginal discharge for the past week. She reports that the pain is worse during intercourse and that she has been experiencing irregular menstrual bleeding. On physical examination, she has cervical motion tenderness and adnexal tenderness. Laboratory tests reveal an elevated white blood cell count and a positive nucleic acid amplification test (NAAT) for Neisseria gonorrhoeae and Chlamydia trachomatis. What is the most likely diagnosis?