What Causes Painful Spot On The Top Of Head?

I'm a 33 year old female. i've just felt a soft spot on the top of my head. Towards the front, just to the left hand side, of the middle of scalp. It's about 2 inches long and 3/8 of an inch deep. It hurts internally when touched with pressure afterwards. Almost like a migrane pain. The pain goes away within a minute, but it does continue to ache. Is this something I should look into?