When is it safe to start running and working out post BBL?

I received BBL on 5/29/15, i will be 6wks postop this 7/10. My dr told me start working out 2 weeks postop, which i did. I didn't do any cardio until 7/6, I ran for 20 min and this may sound crazy after i went running I swear my butt has lost a lot of volume. I read mixed reviews about exercise after BBL, when to start, how much to do. I'm wondering how long does it take for the fat to settle and would minimal cardio (ie running) 5 weeks post-op decrease volume?