So at my 30 week appointment, my doctor told me I don't get anymore ultrasounds. I haven't had an…

So at my 30 week appointment, my doctor told me I don't get anymore ultrasounds. I haven't had an ultrasound of my baby since I was 20 weeks along. How can I go the entire rest of my pregnancy without an ultrasound? That's the stupidest thing I've ever heard. How would they know if something is wrong with my baby or not??