My layman understanding is that Nadir, or low point, of PSA after radiation as primary treatment (RT) can take time measured in years to reach.
And the Nadir for RT is higher than the target PSA after RP because there remains a prostate.
I am reluctant to "cite" numbers, however literature suggests that your PSA is still at a very low level.
Best wishes.

And I would defer to your RO for an analysis, which again, at .03, should be positive/supportive/comforting for you.