Could this be concussion?

[Warrg]

Yesterday I suffered mild blow to the head. I have hit my head many times before, much harder than yesterday and yet, I've never experienced any symptoms that might be indicative of concussion. Yesterday, however, I felt a bit dizzy for a few minutes immediately after having been hit. Also, 15 minutes following the blow, I started to feel a bit nauseated. The nausea lasted for few hours, but it was really mild, so mild in fact that I haven't thought for a single moment that I might throw up. When I went to bed I started to feel dizzy again. Dizziness seemed to be triggered by my changing  position while in bed. This morning I felt fine until I went to bed to have some rest. This is when dizziness came back again. I still feel light-headed. Taking everything into account, could this be classified as concussion? Just to point out: I didn't lose consciousnesses even for a moment, I didn't experience headache, my mental state isn't altered (nor it was immediately after the blow), I have recollection of everything that happened prior and after the blow. The only thing that's bothering me is the fact that almost 24 hours after being hit, very mild dizziness persists.I considered going into ER, but I figured it might be unnecessary since I'm not feeling dizzy all the time and when I do it is not intensive. My point is that the symptoms I have experienced do not interfere with my daily routine, but since the symptoms present are usually associated with concussion I'm wondering if I should, nevertheless, see doctor. I'm aware that this is, in worst case scenario, mild concussion, but I'm unsure whether I meet criteria for actually getting that diagnosis. I would really appreciate advices. ER is quite far away, so I wouldn't want to go, just to find out that I'm perfectly fine. Thanks in advance.  

[Warrg]

Thanks for your answer!