It really sounds to me like the power of suggestion is working against you.

MY advice is to watch your thoughts, and when they start to stray into this territory (where you are imagining all the things that could be causing this strange feeling;) "interupt" your train of thought and tell yourself "Stop that, we will know what is going on when we speak to the doc about our PET."

Then, Immediately turn your thoughts to something that has no associations with your recent treatments or your body.

Take some time right now, and list a few subjects that fit this, and then keep the list with you. Work on this, it does work! It will help you keep calm.

Drink beer if all else fails! (just kidding, do not drink when you are having fear and anxiety, it will only make things worse)

Or get a book with a positive theme, and read it, but keep your guard up by monitoring your thoughts and keeping them from straying into this mental minefield of playing "I wonder if this could be..."

Don't do that. Be vigilant, keep your thoughts positive.

We program ourselves with our thoughts, be aware of what's going on in your head, and take command. It's your mind, they're your thoughts. Direct them in a positive direction.

And please keep us informed when your learn what the story is.

We care!