I have a pair of 6's from abercrombie (from High School I'm sure) that are easily 8's or 10's ... but say 6
I bought this gene skirt from Old Navy that said 2 and I was NOT a 2, but it fit... (i've never worn it, but it's in the closet)
I can fit in the 28/34 from Guess & Seven Jean I bought, but tried on that size in others and the seams were splitting (speaking past tense).
The brand, cut and whomever is manufacturing/sewing the clothing items put that # on there as a 'guide' ... You are above this SG.
It is very hard to remove yourself from the sizes on the clothes you love or love to fit into ...
We all have those days where we feel bloated, FAT, pissy, uncomfortable, like a lard ass, when we know we're not ... and think "dammit STFU & let me feel sorry for myself" ...

But that doesn't mean I won't call you out on it and tell you others would kill to look as good as you do ... I would expect the same from you when it's my day to be a brat ...