Wow at the guy who mentioned cancer, woah... he/she doesn't know a single thing about medicine... that is fine, what isn't fine is suggesting such a thing! You don't have the medical training to do so, specially only, cheesh...!
Creolena: Don't worry. I had the same issue some days ago, it was mostly because of my migraines. It's common to get that kind of pain when you suffer from migraines. If you haven't suffered from this before, then you should really go see a neurologist. Actually that kind of pain, specially the one behind the head and is accompanied by neck and shoulder pain is often caused by tension. There are soooo many different things that could be causing your headaches, and I'm happy to tell you that cancer is rarely the source of that, so don't take what that guy/girl said; he/she has no idea what the heck she/he is talking about. Just go see your neurologist. If he asks you to get a MRI of your head done then go for it, don't accept a CT scan tho; too much radiation and in most of the cases a MRI is far better (specially when we are talking about the head).