OP here, I did have an HSG. The results were very confusing and so hopefully the new RE can be more enlightening.
During the test, the tech forgot to take pics, and the doctor may or may not have looked at the results as they happened. They got into an argument afterwards about why pics were not taken. Anyway, altho no one saw fluid travelling in the tubes, there was fluid at the end of the tubes, suggesting the fluid/dye had made its way through. I am trying to believe everyone did their job and they're confident with hte results. I would have had more faith if the doctor watched it all happen, and there were pictures to back it up or something....