Were they able to confirm that it wasn't ectopic? I'm a little concerned, because there has to implantation somewhere in order to produce HCG.
Where is the pain located? Are you still having bleeding, or has that lessened?
It is possible that the pregnancy implanted, and then was reabsorbed by the uterus, but there should still be changes in the uterus size, and also the lining.
For example, with my d&cs, my uterus always measured the gestational week that I was actually in, regardless of the fact that the baby had passed (only a couple of weeks earlier)
As far as the pain, well technically speaking, even if the baby was reabsorbed, the cramping and pain is supposed to be helping the uterus to contract, and expel the extra blood and lining that it was storing for the pregnancy, as well as contract the uterus back to non pregnant size.
For the radiographer to say that your uterus "has not been pregnant", then I would be very concerned that the pregnancy may not actually be in the uterus, which can in fact be life threatening.
Are you able to get a copy of the films/reports, or have another doctor review them?
Are you just waiting for HCG results? If so, they are not going to tell you much unless you have something very recent to compare them to (do you?), as in within the last 48 hours.
Thinking of you x