Even if you could get the scan, at such a low PSA reading the chance of them being able to see where the stray cells are is very low. Your surgeon will probably use all the information from your pathology to determine where the cells might be - r will refer you to oncology who will do the same. As the pathology indicated that the cancer had been near your bladder, they will probably recommend that you have adjuvant RT to the pelvic area.
John had his RP 10 years ago and they had to remove a bit of his bladder and remodel - he had RT & HT 8 years ago and is fine.
There is no reason to panic and think everything has to be done urgently - apart from anything else, your PSA doesn't seem to be rising at any speed so it isn't like the cancer is marching around your body.