Why does the bump where i hit my head keep coming back?
 

Its weird it just came back right now and its like the 3rd or 4th time its come back. its no where near as big but its in the same spot and its tender to touch. it will most likely be here for a few days then go back to normal and feel normal agian.

should i be concerned? what could it be

Where is it on your head ?
What does it feel like, hard, soft, changes slowly under pressure ?

its on the side of my head towards the back where your head rounds off alittle

it kind of going away now but its disurbing becauses its in the same exact spot as the mega bump i had when i first hit my head. it feels kind of hard and ive been getting weird sharp pains coming from the area all day.

You may have a strained ligament or tendon or a bone spur at a tendon or ligament anchorage. A slight strain to inflame that injury could cause the swelling.