I assume that you have never had any other PSA test result to use as a baseline?  The normal range is between 0.0 and 4.0, however elevated PSA's do not necessarily equate to prostate cancer.  There are numerous reasons and possibilities for an elevated PSA.  If you are having any other symptoms, such problems in urinating, discomfort, or frequent urination these could be triggers of other things.  Since you an appt coming up in Oct, it is likely your doctor; hopefully a urologist will give you a clinical exam of the prostate and perhaps even recommend a transrectal biopsy of the prostate to rule out cancer.  Several infections can cause an elevated result, but early detection is greatly on your side for diagnosis and possible solutions.