Hit head yesterday, had a lump, went er. i was discharged. since then, almost every time i blow my nose, there's bloody mucous. what do i do?

Depends: ...On where the "lump" is/was. If you were hit in the face over the sinuses (forehead or cheeks) or in the nose, it can be normal. If hit anywhere else, is odd and should go back to er for recheck.

See your doctor: I would follow up with your primary care doctor for further history and evaluation.

Nasal saline: The bleeding is likely from the initial trauma. If there is no active bleeding, just blow gently. Use nasal saline to keep the mucus moving and the nose moist. If the amount of bleeding increases, see an ENT doctor.

Be seen again: You need to let your doctor know right away that this is happening. You need to be checked again and further evaluated for damage from the head injury. I hope it is not serious!