Mine also come about when either I am stressed or having anxiety, or over thinking something to much.
Thank You very much for the advice...
Well, first, it will probably take more than a week for the marijuana to get completely out of your system, so give that part some time.
PAC's/PVC's are largely associated with anxiety and stress, for me, the more I am stressed or worried, the more I notice them.
If you want to stop them, I would suggest trying the herbs called Hawthorn Berry and Mother wort, I just started this blend and they have helped a little already, it takes a few weeks to really take effect, but I am hopeful that it will be a full recovery or at least 90% better, it actually is 70% better already.
Since you have been tested by your doctor and been told all was well, it probably would be OK to start doing light exercise until you get your confidence back up, in time, this should pass, and if not, know you are not alone, this is a problem a lot of folks have, even with healthy hearts.