Ultrasound test shows normal size of prostate, psa: 1.0, urine/semen cultures clear of bacteria, 2-3hpf of pus cells in semen culture. is this all enough to conclude that i don't have prostatitis?

Maybe : Prostatitis is most commonly caused by a bacterial infection. Determining which bacteria is the culprit may be difficult since prostatic secretions not always easily obtainable. Also, some of the bacteria implicated in this condition may not grow on routine culture mediums. As such, the initial diagnosis & treatment of prostatitis is largely based on clinical grounds (i.e. Symptoms & exam).

Prostatitis: Prostatitis is a "clinical diagnosis". There is not a test that confirms or rules it out. Diagnosis is based on digital rectal examination of the prostate and more importantly, your symptoms. Ultrasound has no role in diagnosing prostatitis.