go to the doctor...

Go see a doctor anyways, humans aren't supposed to cough blood on a regular basis. Also, the Internet is a bad place to get medical diagnosis.

Why not? This is your health at stake here, for crying out loud. This doesn't sound like a flu, it honestly sounds like something that can land you in an ambulance if it gets worse enough.

Goodness, I can't believe how the American health care system has led people to have this line of thinking there...