With a Radical Prostatectomy, the bladder is stretched a bit from the shortened & re-sutured urethra.
Letting the bladder fill to capacity will typically slowly bring you back to close to your pre-surgery capacity. It takes a little more control with a little more capacity.....
While pad-free since week 14, it has taken me almost a year to get to that combination of control AND capcity. Being very active, I often drink over a quart of liquid (e.g., water, low-fat buttermilk, or tea & lemon) in a short period of time and just recently have found my trips to the restroom less frequent -simliar to pre-surgery days.
A full bladder is also good practice for your recruitment pattern of your pelvic floor muscles.
You might also try to "hold it" while you cough with a full bladder while standing over the toilette just before you go.
Until week 20 or so I would exercise walking up and down the stairs nude from the waist down with a styrofoam cup with a full bladdder and coughing.
It is a humbling experience!
But then just being continent with an empty bladder is not good enough!
And who knows when you will cough or sneeze or lift something while turning, etc.
Barry's surgeon's point about going frequently is helpful while the area is still most traumatized. You are coming up on 7 weeks and it is your call.
I agree with James about emptying the bladder before retiring.
Still, most often it was when I awoke that I had the best practice coughing with the most-full bladder.