Take my advice Stef, I found a dress in pronuptia last year and ordered it, I was a size 18-20 then, felt great in the dress. I totally wrote off the original dress I wanted because it was too expensive and it was a slimmer fit too.
I went for a fitting in my dress at the shop and it fit, I ordered it two sizes to small. But something didn't feel right in it. Anyway 3 weeks ago I saw the dress I set my heart on, on sale for £400 it's a £1400 dress! It was also size 14! Couldn't believe it. I talked to OH and I decided to go for it, it was at a shop on manchester so I bought blind.
When it arrived, oh my god, beautiful! I was everything I wanted and more, I went to my mums house and tried it on, perfect, still need to lose a stone to fit perfectly in it, but oh my god, I am so happy that I got it, Ive left it withmy seamstress and shes going to tidy up a little beadwork, but apart from that it's perfect!
It pays to wait, you may find a dress now you love and when you're much slimmer next year you may want something totally different, it's been the case for me. I'd say wait. On the other hand if it's cheap and in good condition, you could buy it and when the time comes if you want another one, you could stick it on ebay/preloved etc. There are plenty of brides out there hoping for a bargain dress! xx