Everything is fine! The doctor and the tech both looked at everything and said he looks perfect. They seemed a bit baffled as to what the other guy was talking about in his report. The doctor said maybe they saw the umbilical cord or the gall bladder and thought the dark spot might be fluid. He showed me all the places the fluid should be and said everything looks great. So... whew!!
I am tired from the stress but so relieved. It's annoying that they scared me like that, but I did get to see Little Dude for awhile and that was great, too. We got a perfect view of his boy goods, confirming that he, in fact, is a dude.
Thank you all so much for your prayers and thoughts and encouragement!
Here's a thumb-sucking picture for you: