Generally, you should buy maternity clothes in your pre-pregnancy size. As maternity clothing provides extra room around the belly and bust, it gives you the comfort you need for your changing body. If you're in between sizes or are still unsure of what size to buy, consult our maternity wear sizing chart. Take measurements around the fullest part of your bust, your hips (under your bump), and your bump circumference, and compare these numbers to the sizing chart to find your ideal fit.
Ok so I HATE maternity clothes... or I should say hated... I bought my first pair of maternity jeans yesterday from primark of all places and I am literally in love! They are still nice and skinny and fitted but so comfy around my bump - check out my maternity video on what I purchased here; https://www.youtube.com/watch?v=r3bLjGSHMZE&index=3&list=UU-DxGKz7B0xh_zSDzgnL2cw