I am 26 weeks pregnant with twins, and I work full time.  I was wearing "the best" maternity/nursing bras, along with a support belt, but my back still hurt constantly (in addition to the pressure in my stomach and pelvic area. I wear the bellybra without a bra, and my breasts are fully supported.  My back does not hurt anymore.  My breasts, stomach, pelvic, and back feel totally supported.  This product does what it advertises to do.  I highly recommend it! Oh, in regards to sizing, pre-pregnancy I'm a small woman - size 4 - bra size 34C; I bought the medium and it fits well.  THe small would have been much too small.