Overwhelming sense of “doom”?

Before I start, I haven’t had any anxiety problems in my life not even for tests in high school which is very weird I guess? But here it goes, I have an overwhelming sense of doom like something is going to happen at the hospital and I’m not going to be able to bring my baby home. This has been happening since I got pregnant this baby was diagnosed with Down syndrome but somehow I knew he had it before I even got the amniocentesis!? It wasn’t even a surprise when they called and told me all I said was “yeah I thought so” they didn’t find any signs of downs during my anatomy scan or any scan I JUST KNEW! I asked about getting a blood test done and it came back low risk but I told them do an amino just in case. I was right. Now I’m afraid my feelings are right and I won’t come home with this child, I’ve talked to my doctor she said everything looks fine to her so I went to see 3 therapist they all told me the same thing, if the doctor doesn’t see anything wrong then there’s nothing wrong. But I have a sense of pure doom. Please tell me I’m not crazy and other people have this “feeling” and it wasn’t true. I’m a third time mom and have NEVER felt like this about my other children.