how old are you? was there any pain? go see a doc. could be prostate trouble, do you have any classic prostate signs/symptoms? urinary frequency, urgency, hesitancy, or dribbling?
I had this too. Doc said it is rarely a serious problem. Sometimes related to trauma from heavy squatting. He ran some tests but basically reassured me it was probably transcient and will dissapear. I will have test results back soon. My PSA form sept was 1 anything less than 4 is real nice. Over 4 then more tests. Scary as shit but probably benign. Good luck get your PSA checked. Good luck.