As many arguments as there are about
what can / can not cause PSA to be high, all the books and sites I've seen agree that sex within the 48 hours prior will cause a spike in PSA. Others think that abstaining for 3-5 days is best.
So, I agree that a retest is a good idea.
There are both opinions on having blood drawn immediately after a DRE - I had two uros give me opposing opinions. It does make common sense that anything which disturbs the prostate should be avoided (i.e. now that it matters, ask that the blood be drawn first just in case).
I had a "free psa" done after my first/only high PSA, but don't know the result, only that my GP was on the phone with me before putting down the fax to schedule me off to the urologist.
And as always, a word of Welcome. Lets just hope that you come back telling us it was a false alarm. We do allow resignations