Pelvic Inflammatory disease. could the diagnoses be inaccura

Hello, I was recently diagnosed with PID (Pelvic Inflammatory Disease)and from what I've read and the doctor at the hospital told me is PID is usually associated with an STD such as chlamydia and/or gonorrhea. But my chlamydia and gonorrhea came back negative. The follow up nurse said PID could have came from other organisms from the other person. I did have a high fever and high blood pressure so there was an infection present. I'm curious as to what type of infection caused PID if it's sexually related, or could the diagnoses be inaccurate?