I am a very old school Reiki practitioner/teacher who teaches that ours is not to diagnose nor to share impressions during a session.
Had this happened to me, during the sesson I would have made friends with the energy of your body and not been worried that one area was reacting different than another. I would not have judged it good, nor bad, nor dialoged with you about what was happening for me, because it is your session, not mine.
Then, when you got off the table, if you told me that you were having these types of reactions, I would tell you that Reiki works at very deep levels and sometimes a session can bring great peace and sometimes a session can bring things up in your being. But to always remember, if something comes up, it is for acceptance and release.
My job in that moment would have been to make you not judge your own experience, understand that "Reiki works" and that you can take this experience as an opportunity to love anything that's coming up for you.
If someone was still concerned about what they were feeling, I would have them sit again and take them through a grounding exercise.
If someone wanted to speak deeply about things that were coming up to their consciousness, I would tell them that I do not have any training as a therapist and I would be happy to listen and help them feel ok to feel, but I could not make any suggestions for integrating a past experience.
I know this may not be super helpful but just wanted to let you know my role in my experience. I have had many, many people under my hands and just like the intelligence that is you guides the energy for you, the intelligence that is you is the best person to guide you in your next steps. In my experience, it has always worked out.