Did I Make a Mistake??

So a few weeks ago I went wedding dress shopping and I finally found my dress. Now I went to 2 different boutiques and both had the same dress I wanted. one store had the dress in a size 18 which I was able to step into the other store and the dress in a 16, but the only way I could get it on is if I put on over my head. Now when ordering the dress I noticed that I ordered the 16 because I’ve been trying to lose weight for my wedding (so far I’ve lost 22 lbs) and according the Boutique’s measurement sizes an 18 would be a too big(& would cost extra) but the 16 was a lil small. I am 4 inches bigger in the hips, waist & chest for the 16. But I know I’m going to lose this weight. Well anyways I telling one of my friends that I ordered the dress in the 16 since I was able to put it on, but over my head and the sales girl told me Maggie dresses don't really stretch by much (only about 1/2 and inch) So I figure I would be ok. Well my friend is telling me I made a huge mistake and i