@gakelley Oh mama, my heartbreaks for you. I am so sorry for what you're going through. I think finding a malpractice lawyer is a good idea. (Also, some grief counseling for you and your husband.) That way the same thing doesn't happen to the next mom in a similar situation.
My son is six months old now but when I was around 35 weeks or so I felt a lot of liquid and told my OBGYN about it. She sent me straight to the hospital where they tested for amniotic fluid. It came back negative. They still did an ultrasound and monitored his heart rate. They were very thorough. Anyone dealing with prenatal care should be just as if not more thorough. A life literally depends on it.
It's important as a momma to trust your gut but it's just as important to not cause you (and therein the baby) more stress than necessary. It's a fine line to balance. You made the call you made based on what the medical professionals said. It's not your fault that they weren't thorough. Please don't blame yourself. You did the best you could with the knowledge you had at the time.
I read in the other comments that his name was Evren (am I spelling that right?), which is just so beautiful. I love the meaning and that it starts with a vowel. My son's name is Artal, and all our other chosen baby names start with A. Maybe you could do something similar when or if you feel ready to try again. It would be a beautiful way to keep his memory living on with his siblings, something they share.
Anyway, I can't imagine what you're going through. I am so sorry this is happening to you. I am sending you and your family positive vibes