MMR struggle

I've won 11 out of my last 12 and my MMR still hasn't moved. I went on a losing spree a few days ago and dropped outta plat but now i just won 10 in a row, and then won another after a loss and got back into plat. Why is my MMR still at 1600? I really don't think that's right considering i've been carrying my team pretty hard for 10 games.