What size should I get?

I’ve been dieting and I’m 90 pounds down (original weight was 265, now I’m 175). My goal weight is 150 and I’m 5’6. I won’t reach my goal weight for a couple of months, but I see a really pretty blouse I want to buy that I can fit into when I reach my goal weight. I need to buy it now instead of waiting because the store won’t sell it for much longer. If right now a large fits me perfectly, would a medium fit me when I lose 25 more pounds? What size should I get? (For reference I’m currently a size 14 jeans, I only dropped 3 pant sizes even though I lost 90 pounds)