22 days is awesome -- thanks for giving me the inspiration to go 21 :)
I started my cleanse on a particular day in part because of what you mentioned above (i'm on day 2 of my cycle) and am hoping that the Master-Cleanse will curb the PMS symptoms I have (which are more severe when I'm loaded with Sugar and carbs). In short, I expect that next month my cycle will be less painful, and I will have next to none PMS -- as that is what happened last year when I did a 15 day MC.
You're enjoying the benefits of the Master-Cleanse -- no PMS. If you've been regular, I'm sure your cycle will start soon (but could be very light).