I had mine at 6 weeks. Did not provide number but stated undetectable. I had a bad margin and got upgraded like you to Gleason 7. They are anticipating me getting radiation at around the 3 month marker after I heal more but I am betting that if my 3 month PSA is significantly less undetectable than the 6 week undetectable they may reconsider. I will kick my heals and howl at the moon it that occurs.
I guess I am saying it depends on a lot of things such as your situation and your Doctor. No matter what the number or time they take it they cant do anything now for you need to heal more. You should have a 3 month re-examine with your Surgeon.
I was tempted to ask for the exact numbers i.e. .005 or .00005. or whatever but I guess I just want to get on with this, what ever I need to do I will do. In the meantime I am going to livvvvvve and be free.