Feels like brain is swelling. Could it be Brain Cancer?

Hi! Well first of all I'm new and this is my first question topic thing and I have no clue as to how this works. Anyway: I've been sick lately and now suddenly I have a big discomfort in my head. My head feels like my brain is growing or something. It isn't really a pain but I just don't like it. I remember reading something about a girl who's head felt kinda like mine does and it turned out she had brain cancer. I have a family history of cancer so I got a little worried. Is this just a side affect of me being (somewhat like post viral gastritis) or could it be something serious?
I'm not entirely sure if this works like other cancer and you have a tumor or something.