How Long Do I have to Refrain From Lifting After A Chin Implant? Could lifting before 3 weeks increase the chance of infection?

Weightlifting is one of my passions and with that being said it is very hard for me to be apart from it for long. However, I do understand the importance of laying low after surgery but I am wondering how long and why? It is exactly a week from the day that I currently had surgery and my plan is to not lift for a month in fear of the implant shifting or bruising even though my surgeon said I would be okay to lift heavily after 16 days. Can anyone explain the importance of not lifting post-op?