I got elbowed in the forehead and received a big bump and a black eye. The black eye went away but I still have a bump there. It's been almost a month?

Probably.. The bump was a hematoma (collection of blood under the skin.) these will often become fibrotic (scarred) and last for months. They are almost never permanent. You may be able to hasten the disappearance with gentle massage of the lump. I would give it about 6 months to disappear before doing anything else.