My partner woke up bleeding four weeks after prostatectomy.
We searched Internet for related stories, and found one on this site of a man who walked ten miles after prostatectomy, and then began bleeding.
Similarly, feeling well, my partner engaged in an cross country skiing one month after surgery-he felt great, but then woke up unable to urinate and bleeding.
Pressure and pain grew, bleeding continued. Clearly the bladder was blocked.
Brought partner to emergency room. They put catheter in place which relieved the pressure--clots were released, but some blood remained.
Later, partner received "hand irrigation" technique which was able to remove many clots, and sent home with catheter. He felt relieved, but clearly a set back after a good recovery.
Since there were few to no stories like this to refer to, I'm sharing this story. I'd advise anyone who is experiencing bleeding after a similar situation to get help sooner than later and to have their surgeon consult with any emergency care about best next steps.
Good luck. I'm glad this forum exists.