It's OK to double-up on classes, if you enjoy that and have the capacity, but having a 3rd day of exercise would also have a different impact (I think) on your blood sugar for that day, so I think having more exercise days is a good thing. There are lots of factors to consider - your general energy level, your eating habits, how it effects your sleep, etc. etc.
I say just enjoy exercise as much and often as you can, and the rest will likely work itself out...
Nothing needs fixing