I am going to be a bridesmaid in a wedding, I am still trying to lose 25lbs, I've already lost a lot of my

weight that I gained while I was pregnant last May from my daughter. So I only have about 25lbs to lose! My sister in law, is making all the girls buy a dress online, that we orginally tried on in a bridal shop. We found out it was way cheaper to get it online! So now, I am scarred should I go get my measurements done and order based on what my measurements are now? Or should I go a size smaller? I am on the atkins diet, and I go the gym everyday lift weights and run on the treadmill, so I am a dedicated gym person! I know I will lose the 25lbs, but I heard that when you lose 10lbs that's a whole dress size! So any suggestions on what I should do? Would a tailor be able to alter a dress if it's too big? We have to order these dresses this saturday, we are forced to order these dresses now, because if we don't they will not be here on time before the wedding!