Looking into getting one of these as having real trouble with my hips. Plan to see midwife too but can't get appointment yet. Am i being thick, seen sizing guide but what am i measuring (hips, bump?) [[http://www.boots.com/wcsstore/cmsassets/Boots/Content/Products/Pregnancy%20and%20Prep%20-%20CAT:%20A00000160/10107692.P/Canatloop%20Support%20Belt%20Sizing%20Chart.jpg here]]