Almost choked on a ball of blood. thin layer of clear mucus around in it but primarily bright, thick, blood reaking blood. throat not sore. what's up?

Look at nasopharynx: Bringing up blood with mucus suggests there is a source of bleeding from the head and neck area and not regurgitating blood from the stomach. Since there are no symptoms related to the throat refered to as oropharynx I suspect the problem is bleeding behind the nose in the nasopharynx. If persistent this can be defined with a transnasal laryngoscopy catheter and a bleeding site cauterized