Born this way -- You should definitely buy one nice pair of jeans now. Seriously, jeans have at least 7 lbs flexibility, and also: TOM jeans!! Who doesn't have a pair of bloat jeans?

The slightly too-tight going-out skinny jeans of today are the comfy fat jeans of three months from now!
I'm only being slightly facetious. I just bought retail-$150 jeans from Habitual ($50 on clearance online) that fit fairly snugly now and will hopefully be my slim-but not-tight work-appropriate Casual Friday jeans in a few months.