PCR and related tests are the methods of choice for detecting chlamydia. A single test will pick up over 95% of infections, far more accurate than other (older) tests.
HHH, MD
Doc, as a point of referance, with regards to the chlamydia tests nowadays. Is there any data how accurate the PCR urine/swab tests are?
I wish I could help, but I cannot make even an educated guess about the cause of the transient pelvic pain you describe. It seems consistent with PID, but also with so many other things. PID sometimes is due to non-STD infections, but even in people with negative test results for gonorrhea and chlamydia, PID usually is sexually acquired.
But even if it was PID, the normal pelvic ultrasound suggests that no serious damage was done. That isn't proof, just changes the odds in your favor; but there is no particular reason for you to be frightened about infertility, tubal pregnancy, or other complications of PID.
Sorry I can't be more helpful. Your gynecologist is in a better position than I am to judge whether you are at risk for infertility. But my guess is it's not a problem.
Good luck-- HHH, MD