As the presence of blood is present when you coughed it should be examined. Its likely to be just a small lesion due to continuous bouts of coughing, but it should be confirmed. I would advise you to meet a MD general medicine/pulmonologist so that you can be examined and undergo investigations such as X-Ray chest, CT/MRI (if indicated), CBC, etc to find the underlying cause of the problem and have it treated accordingly. You will need an antihistamine and a cough syrup to control the situation.
Next Steps
Follow the steps as advised
Health Tips
If condition persists or worsens visit the ER at the earliest