This is a test of commonsense. Complete the next sentence:

How to buy a nursing bra
Find a trained professional to measure you to determine the correct bra size.
Work with a professional trained in measuring bra sizes or a lactation consultant. While you can measure yourself, you'll get more accurate measurements if someone else does it so you're not shifting and moving around during the measurement.
Most lingerie stores or maternity stores offer free measurements. Get fitted before the baby is born.