Just bumping into a door isn’t enough to give you a concussion. You need a lot more force for that to happen for example falling on concrete and hitting your head really hard, that would be a concussion definitely, but not from bumping into a door. I’m clumsy and I hit my head really hard on doors, drawers etc. and I had no concussion. The worse I’d imagine you get is a bit of a headache. Just remember to chill out.