I brewed an Oktoberfest 7 days ago that started off with an OG of 1.040 (which I know is a little light for an Oktoberfest). I just checked it and it's at 1.020. The taste was pretty good but I'm worried that it didn't ferment all the way. I noticed that it was only actively fermenting at most for a day and a half. Should I think about repitching since I'm still in my primary?