How far along are you? I had similar things happen to me. But I know if your early on in your pregnancy baby is still small so it's harder for doc to see everything. My story is very long but to make it short, they told me the same thing but later on they said baby is ok. I also took the blood test for Down syndrome and everything came back normal. So just stay positive, praying all goes well for you.
I'm 13 weeks pregnant. I'm hoping everything will be okay but i couldn't get in to have another scan until I'm 16 weeks