Best pregnancy support band for lower back pain?

So I'm 5'1 and very small framed, and I think that's part of the reason that this growing belly is putting such a strain on my back. It hurts so bad sometimes I can barely stand up or even lay down in bed comfortable and wakes me up at night. I'm only 18 weeks so I imagine it'll only get worse..... what would be the best band to get to help with lower back pain?