Hi, for the past two or one and a half weeks I've had a slight headache about every day or every other day and they each last about 20 minutes. The pain is mild and it goes away quickly. However, I've noticed when I think about it, it lasts longer, so whenever I dwell on it, I notice it. When I'm not thinking about it, it's not there. I don't know what kind of headache I have so please help me out.