Size 22/24 what size will I be in a Bridesmaid's Dress? Please Help!! Fitting Tomorrow!?

My friend has a wedding come up 10/08, she wants us to get fitted and order the dresses by 12/07. I've lost all this weight before, and I'm working on doing it again for this wedding, but I'm a 22/24 now so I'll have to order it at that size, and then in June of next year get it taken in to the new size that I am with the weight I've lost. The dress she picked goes up to a size 28, I've heard bridesmaid dresses run small, so I'm hoping I'll at least fit into a 28?? Anyone been in this situation before? I'm MORTIFIED to go get measured tomorrow, so nervous!!