I did what dizzy did - although I was seeing the physio about my sacroliliac joints coming out, but when I went back for follow-up appointment I said my back was fine but I had lower bump pain and she gave me several belts to try on, including an Emma Jane one. I came home with a belt and an enormous length of tubigrip. It helps a lot but I've had to ditch it in this heat!
Your midwife should refer you, especially as your so uncomfortable so soon.