Today when one of my roommates came home I got up and kinda ran to the bathroom. When doing this I put my shoulder to the door to open it but didn't turn the knob all the way so I hit my shoulder and hit the side of my head slightly. This was 3 hours ago, I know have a headache on that side near the spot but the problem is I usually get frequent headaches and have had a more mild one before this event. Also when I came back home and ate I got quite drowsy, struggling to stay awake. I have experienced this drowsiness before on one other occasion where I hit my head and ended up going to the emergency room which ended up with them doing reflex tests and say I was okay. Sometimes I worry and I've already been to the emergency room for frequent headaches, so should I be concerned? Also the door is pretty lightweight and maybe I'm worrying, but I don't understand why I'm so tired and I've had the headache for around 2 hours on the right side.