HI Mark,
I've been clear now for 7 years (testicular, both barrels).I'm no expert but some thoughts based on my experience.
At the moment you've no diagnosis so try not to worry. Easier to type than do.
If the NHS staff that looked after me are anything to go by then you're in good hands.
I guess Meg will be with you when you see the doctors, you'll both have loads of questions so best to write your thoughts down before, as a reminder not as some sort of form for the doctor. No question will be the wrong thing to ask and they will have had them all before. I went alone to my first meeting and wish I'd taken notes on what I was told. In some cases you can get info from NHS direct if you think of things after seeing the doctors at your local hospital.
Macmillan staff are worth their weight in gold. Talk to them, they will help you both.
When using the web for information be aware that UK treatment may be different to that in the US (for example), if was for my diagnosis.
In the CT machine don't look at the red flashy light 😉 and definitely (this is important) DON'T go for a piss if you're half way through drinking some odd tasting liquid for the technicians in the CT scanner. I did for my first one and ended up having an injection of a marker dye that gave me the odd sensation of wanting to go for a piss through my left big toe. Only way I can describe it, very, very odd.
Hang in there.
Good luck.