I'd be patient and let several months or even a year go by. In seeing weight loss on others who've lost a fair amount of weight (I have no recent personal experience), it seems the skin sometimes takes awhile to catch up. But often, it does. The best thing we can do is exercises to firm the muscles underneath (which add shape and tone us up) and follow a healthy diet with lots of good fats, vitamins and antioxidants, right?
When thinking about my own future thin body, I do wonder if I'll have loose skin. And I've decided that it doesn't matter. I'll still look heaps better than I do right now.