HillRom sent me my full vest post partum based on my bust measurement-they said it had to be fit based on my widest part. I have 4 vests total- chest vest for giant pregger belly, large vest for giant milk filled boobs, medium for weight loss and boob shrinkage and small as my final size. HillRom questioned my vest orders but I explained the situation and it was fine. Maybe call and ask what size bust your vest is meant to fit?