Your PSA test will read higher if you have exercised your prostate within 4 days of the test, sometimes higher enough from your normal reading that the Doc may want to do the biopsy test. NOT a pleasant experience, from what others have told me. This was confirmed by my Doc, when one of my tests came back at 1.7, when previous tests had read 1.4.
I asked him whether activity affects the test, as he was prepared to send me for the biopsy. Apparently a rise of just .3 is sufficient to warrant further investigation. Once I retested, without exercising the prostate for more than 4 days, the numbers went back to 1.4.