What Is The Treatment For Chronic Cough?

I have been having chronic cough for the past 3 weeks. It started with a simple cold and fever, even though the fever and cold died down, the cough has persisted. I took antibiotics and anti allergy medicine for 5 days, and though the cough did get better during the course of taking the medcine, it has come back again. I got a blood checkup done yesterday and my esr has been reported as 45. Everything else is normal. Also, I have no other symproms like fever/headache etc. Also, th cough increases if I do an intense physical activity. I am on anti-allergic medicine again.