I had this around the same time @ 6 weeks. Hubby had rubbed my back gently seemed to work. It'll pass around your 2nd trimester as mine did. Hopefully as you know we all experience differently.
I get this too and only at night am 15 wks and 1 day along I got this very early on too I just take paracetamol and heating pad x
I know how you feel this is my second pregnancy very different from my first and she always has the hiccups lol. The best thing that will help the backaches is a heating pad or a hot towel that will help, I have those sometimes