Carlos, you are understandably concerned, but it seem you are getting all the right attention and tests , and are getting them done early. So you are getting the best care.
My experience (search my prior posts). I had Robotic Surgery mid-December 2019. PSA 6 week post-surgery was 0.09. Then three months later, PSA rose to 0.33. That triggered a whole series of tests -- Bone Scan, CT Scan, and PSMA PET Scan. I'm in Canada and am being treated at the top cancer center here. Fortunately, they are a clinical trial for the most sensitive PSMA PET scan (using the F18-DCFPyL radiotracer) -- this is only available at present in the US and Canada as part of clinical trials. In the UK, I believe the most sensitive scan is the Ga68 PSMA PET scan (it's one of the best available, but not quite as sensitive).
The F18-DCFPyL PSMA PET scan I had did not pick up anything (which is more good news than bad news). Since no specific site was pinpointed, I had 6.5 weeks of salvage radiation to the prostate bed area (with targeting based on post-surgery pathology). I was due to see my surgeon, so I had another PSA test only 3.5 weeks after SRT (really too soon - oncologist warned it could be higher, but might as well do another test to get another base point). The PSA result was 0.08, so lower than after surgery.
Here a good article on when salvage radiation is useful: https://www.hopkinsmedicine.org/brady-urology-institute/specialties/conditions-and-treatments/prostate-cancer/prostate-cancer-questions/two-studies-help-you-decide-when-to-pursue-radiation-after-surgery
If you do get Salvage Radiation, it may be with Hormone therapy or without. This site is the best site I've found for sharing experiences and learning from others. When I was getting ready for Salvage Radiation, I knew from this site to ask about Hormone Therapy (most here are getting HT with SRT). My oncologist recommended SRT without Hormone Therapy for me, based on my situation. Lynn asked me a question in another conversation, prompting me to into this some more. This article from the Journal of Radiation Oncology explains that it is an oversimplification that all men undergoing SRT should have Hormone Therapy. (two links to same article)
https://www.redjournal.org/article/S0360-3016(18)31032-0/fulltext
https://secure.jbs.elsevierhealth.com/action/getSharedSiteSession?redirect=https%3A%2F%2Fwww.redjournal.org%2Farticle%2FS0360-3016%2818%2931032-0%2Ffulltext&rc=0
The key Q&A from the article which explains why they do not recommended HT with SRT in all cases is:
Question: What do you mean by clinically meaningful endpoints?
Answer: The reason we treat patients is to improve their quantity and/or quality of life. Things that affect these endpoints are clinically meaningful. Things that simply alter a laboratory result, such as the PSA, are not clinical benefits.