Hello,
I am getting married next week at 35 weeks pregnant. I was sooo worried about my dress and was the one thing making me think to move the wedding. I really have still got the perfect dress and even if I wasn't 8 month pregnant I would still have the dress. I spoke to ALL the dress shops in my area and they all said you don't need a maternity dress and showed me the sort of thing that would flatter a bump. I will post some pics when I get them.
If you need any advice definately speak to the shops, it's far more common than you think and they know what sort of thing to expect. Also try dresses on with cushions down you! Gives you an idea at least. I got one size 14, normally would wear an 8, got a lace up back for easy adjustment and all I had to have admendment wise was the top part taken in and only cost a few pound to get changed xx