PSA Doubling time

I'm 63 years old and my PSA was 4.1 two months ago ( in 2008). My doctor was concerned and referred me to a urologist who said he noticed slight something upon digital exam. He said stones in prostate are known to exist for many people. My urologist gave me Cipro for two weeks and repeated the test. Now total PSA is 1.5 and free PSA is 0.4. Ratio of free to total is 0.27. So, PSA came down from 4.1 to 1.5 after antibiotic treatment.

My PSA was 1.0 about 16 months ago (in 2006) and 0.9 a year before that (in 2005). I calculated the PSA doubling time using the calculator online:

From 0.9 to 1 (2005 to 2006) PSADT = 76.3 months
From 0.9 to 1.5 (2005 to 2008) PSADT = 38 months
From 1 to 1.5  (2006 to 2008) PSADT = 28.1 months
PSAV for all above calculations = 0 ng/ml/year

I'm worried that my PSA is increasing as shown by the doubling time. Is this to be expected with age?

My urologist wants to do imaging and biopsy, if needed. My appointment with urologist is not for another 10 days.
I'm OK with ultrasound imaging but am not too comfortable with biopsies. I read that there are possibilities of bleeding and infection with biopsies- is it true? How common are bleeding and infection associated with biopsies?

Does anyone relate to my situation to guide me? Should I be concerned at my age?

Thanks.

[keyzersoce]

I think you have a better chance of getting your questions answered by posting in the Prostate Cancer Community section of MedHelp. Good Luck!