I am 4.5 months pregnant and still wearing all of my regular clothes thanks to these bands.  I bought the black, khaki, and a tan/pink designed one and I love them all.  For work, I use the black and khaki ones - I put it on inside out, pull my skirt/pants/shorts over the bottom of the band, zip up as much as I can, and then fold over the top of the band.  The band itself is a little wide for me right now, so this fold over trick really helps me out.  I'm sure once I get a bigger bump I will be happy for the extra width.

As for size: Pre-pregnancy, I was a size 10.  I bought size 2 in these bands, and its a perfect fit.