Nervous

The sonohysterogram is tomorrow at 11am. I'm nervous. I've read that this is less painful than a x-ray HSG, but its not the pain I'm worried about. If I can give birth without so much as an advil, then I should be able to deal with these "crampy" tests. What I am worried about? I've also read that the sonohysterogram is better for observing uterine issues, but that the HSG is better for tube issue identification. Both have their limitations. I just don't want to waste drugs or IUI's. I have no reason not to trust this RE. I just hope this test is the best choice for me at this time. All I can do is hope and pray.