I fell and hit my head on the floor this morning. tonight, the pain has spread to the front of my head around my eyebrow. should i see a doctor?

Head trauma may just: be a bruise, but it can also be serious, I would see doctor asap to rule out concussion or hemorrhage.

Head injury: Although you did not lose consciousness, you may still need an evaluation by a physician. Some head discomfort is to be expected, but if you note severe or worsening headache,nausea,vomiting,drowsiness, or visual disturbance,an evaluation in the hospital emergency room tonight is mandatory.