Knee swelling for second time after ACL injury

Hi, this is my first post here. I torn my ACL, saw a consultant and a surgeon. After almost a month, the swelling has reduced and I was supposed to get my first physio appointment tomorrow. Here is the trick: I did a bad move yesterday my knee is welling again like weeks ago. I re-lost my mobility (I would say max 90° flexion). What could be the cause of that? I thought the swelling was due to some artery I torn with the ligament but since it was already torn yesterday, why is it swelling again? Also I guess I should cancel the physio ? Thanks for your help! Cyril.