Bronze IV to Bronze II?

Okay, so I'm not entirely sure if this is a bug, but when I went to do my ranked placements I got placed into Bronze IV. After that I played 2 or 3 ranked games, all of which I lost, and somehow I ended up getting into Bronze II. Is this a bug or is it some weird system that increases your rank even if you lose? Another interesting thing is that I have 0 LP, so it's highly unlikely that it was intentional.