Hi T., I don't know where you had the ultrasound at, but if it was at Foote, I'd go somewhere else for the next ultrasound. My brother does ultrasounds, and thank God he does. My daughter had a son 2 years ago, she didn't know she was pregnant for the first three months, she was taking anti depressants which messed her system up. Anyway, one of the meds she was on causes birth defects, she had '3' ultrasounds at Foote, each with a different tech and read by a different radioligist, each one showed the baby was fine. My brother wanted to play with the baby, showing all of us while he scanned her, for fun mind you. He got quiet right away, which I knew my brother, the baby had no diaphram, most of his organs were up in his chest, his heart was on the wrong side, he couldn't find a stomach what so ever, no right lung and I could go on and on. Even after knowing all this, she went to her doctor who ordered another ultrasound from Foote, they still didn't find it. We took it upon ourselves to go to the U of M, they weren't even going to try and save him, they had my daughter sign over his organs before he was born. My daughter got online and found a doctor in Florida who works on saving these babies. I went with her to Florida, she delivered him there, he was treading on thin ice, but I have a happy 2 year old grandson. He has issues, but to me he's perfect and the doctor in Florida, I am so grateful for. He is a miracle worker, a true gift from God.
Back to why I'm writing, the U of M has the best pediatric heart surgeon in the world, I would go see him 'now', he will scan the baby himself from what I understand, and let you know all you need to know. I wouldn't mess with anything else if I were you. At 18 weeks, they can tell the most from what my brother tells me, thats when he scanned my daughter. He works at Bronson. I don't know where you live, but that covers both sides of the state. Get a second ultrasound now, you have the right and reason, and it will help ease your mind knowing what you're dealing with. We researched diaphramatic hernias big time when we found out. And let me tell you, it helps knowing to much than nothing at all.
I wish you much luck and I'll be praying for your little girl:)Sue