Your doc seems to be telling you good info. At 65, with a PSA of 1.2, you probably don't have PC. Swings like that can be from a lot of things, including infection (prostatitis), doing things to irritate your prostate (ride a bike? Have sex?) just before the blood draw, etc.
Hope you keep doing well.
Age at Diagnosis: 56
RALP on 2/17/15, BJC St. Louis, Dr. Figenshau
58.5g, G3+4, 20%, 4 quadrants involved
PSA Non-Detect since April, 2015
My Story: www.healingwell.com/community/default.aspx?f=35&m=3300024