Hi Penny,
It wouldn't hurt to mention this pain to your oncologist at your next appointment. He/she would have a good sense of what's going on and what's causing that pain. To help your oncologist, you may want to keep a log of when the pain occurs, where, what time and what you're doing when it 'hits'.
Your thoughts are normal, I know that I also find that my thoughts go that way when I experience a new sensation in my body. I'm learning to give it time and if the pain persists for more than 2 weeks, I go and see my doctor.