Explanation on placements

Hey guys! I was just wondering the following: Last season I was placed low (silver) and never really ranked fater that. However, Ive been playing games in my spare time and it turns out my current mmr is SIlver 1. As I have not finished my promos, this mmr could get better, or worse. Is it possible I will be placed at my old or at a higher rank than I finished last season? If not, doing my best in these sounds kinda cheap and Id rather just go back to normal. Any of you guys had any experience with this before?