Fitting A Plus Sizewedding Dress

I was wondering if anyone could answer a few questions for me.Is it possibe to get the right size dress without going to an "expensive" bridal store? I took my measurements at home but there not matching the standard sizes that I have been seeing on online size charts. If I must compromise which size do I go by or am I going to have to get a custom made dress. Can someone please help me? Thanks