What to do if i broke my left collar bone and can't workout for 3 weeks how workout with right hand?

Broken collarbone: Has your doctor told you it is ok to work out? If you are clear to work out, you could trying doing some exercise with a dumbell or a resistance band in your right hand. Just make sure you are safe and don't overdo it as your balance may be off. Also, make sure it doesn't cause too much pain in your left collarbone.