Bruise on head, is it serious?

I went to a water park today and bumped my head/face on a slide. I thought nothing of it until I got home. There is small cut but it is red from the middle of my eye brows to my temple on the right side of my head. There seems to be a bruise withing the red. I had a minor headache when it first happened. It is gone now, just sore. could this be something serious or minor?