I'm guessing that they were unrated games, which don't count towards your rating.
rating
You can tell if a previously played game was rated or not by opening it and clicking on the details tab. Today you lost two games in a row against the same lower-rated opponent. Both of those games were unrated.
Tonight I lost 2 games to a player with a lesser rating than I, yet my rating did not go down ? How does that work ?