Ratings adjustments are calculated based on your current rating at the end of the game, not the beginning.
Let me ask a different question that I've been wondering for a while: Does it matter what order your results occur in? Say you're rated 1200, and you have an impending win against a 1000, and an impending loss against a 1400. Your rating will go up for the former, and down after the latter... are you still at 1200 at the end? Do you arrive at a different final rating if you lose then win, or win then lose? What's the "better" result?
How are rating points calculated at Chess.com? That is, when a game is completed, are the players' new ratings calculated using their most recent rating at the end of the game, or are their ratings at the start of the match used?
I've always been curious about that.