Heya,
I'll keep this breif, as for me, when I am in pain, I can tell the levels of seriousness to a degree, like the difference between pancreatitis and a thrombosed hemerhoid.
If you think for even a second this could be bad then you need to go to the ER.
I hate the ER, I loathe it, I would rather pound myself with a hammer then go back to those dungeons they call ER's, but they have saved my life, pancreatitis, acute pancreatitis, blocked bile ducts, etc.
Point is, I to have been way to exposed to radiation, as I believe have we all, we all don't want to go through more body killing testing, but you can control some of that in the ER, when they say ct, you say xray, etc.
If you are uncomforable with something or have a concern, make sure you voice it to every legitimate source you can while in the ER, from nurse, to orderly to Doctor, keep the info coming.
Don't just stay home if the pain is to horrible.
I wish you the best and will be thinking of your quick recovery, I'm sorry your going through this.
Jon