PSA Spike!

I'm a 60 year old guy who has had his PSA checked with accompanying DRE on a yearly basis.  I have also had BPH for a number of years and even entertained the idea of having the green light laser treatment because I feel like one of those guys in a Flomax Commercial.  I entertained the idea of the green light laser three years ago, and I had the scope inserted in my urethra all the way to my bladder. After this exam, I opted for a Flomax Prescription instead.  I never filled the prescription.  Reviewing my bloodwork, I see my PSA was 1.4 in May 2001.  It has made small northward steps since then and was 2.8 in October, 2008.  A couple of times it retreated southward by a few tenths.  In November, 2008, I had Nissen Fundoplication Surgery so I was under general anesthesia for a few hours.  After the surgery, I was having difficulty urinating, and this lasted for a couple weeks.  On December 23rd, I had my PSA tested at the local VA hospital and it was 4.56!!! My physican performed a DRE and said the prostate was soft with no bumps or nodules.  What the heck is going on?  I'd like to think this was a lab error, for how could my PSA rise from 2.8 in October to 4.56 two months later?  I certainly know I had sex in the 24 hours proceeding the test, and I recently learned this is not advised by reading many entries in this forum.  My physician said I could have my PSA retested in a couple months, but I said, "how about a couple of weeks?"  So it looks like I'll be tested in the next week, and I'll take a 48 hour sex break before giving blood.  I'd just like to know what readers of this forum think about such a PSA spike.  Could the general anesthesia I received on November 20th and my difficulties urinating after the surgey have caused such a spike, or does it appear more likely to be a lab error or possibly prostate cancer?  I guess only further testing will provide an accurate answer.