Is Working On Thread Mill While In Pain Post Injury Recommended?

i fell on my left side 9 days ago,possibly bruising my ribs.i hurts to cough and laugh etc but my breathing is fine.i am quiet sore though when getting up from sitting down and with any sudden movements.to have a good cough i have to brace my left side with my hand.i am still doing 5 minutes a day on treadmill with no discomfort to my chest as long as i favour my left side.is this a stupid or good thing i am doing concerning my injury.