Hello Again!
I talked to my sister and first of all, she says she feels your pain and is so sorry that you're going through this!!
She said that there was no specific test to show that anything was blocked. She had to be catheterized several times to empty her bladder because she absolutely could not "go."
She knew she had a tilted uterus from her first pregnancy. This all happened at the beginning of her second pregnancy.
The Dr. said he was pretty sure that, because there were no infections, tests for other things came back negative, and her uterus was tilted, that he thought the urethra was definitely just being blocked by the uterus. He said that it would only be for a short time, until the uterus got large enough that it would not "sink" into that little space. Again, I guess this is only a problem if you have a tilted uterus.
So, not knowing for sure if it would work, he manually went in and pushed my sister's uterus out of the "hole" it wanted to sink into (thus blocking the urethra.)
This worked for my sister! She was "back to normal" with being able to urinate again, but she had to spend the next 2-3 weeks OFF her feet. So, she went to her MIL house and basically laid down or sat down the whole time. Then she came off the best rest slowly so as not to rush anything. This helped her to keep the uterus in the position that the Dr. had manually put it in long enough for the uterus to grow big enough to not give a problem again.
My sis said that maybe you could mention this to your doc/nurse and see if they are willing to give this a try. (Of course, you'll have to stay off your feet for a couple weeks, but sounds like with the terrible pain you've been in that this wouldn't be such a bad option!)
Do you think your interim dr would try this for you?
HTH