I'm not to sure if this is common, but my pimples start out as little white bumps and stay this way for a week-2 weeks before they become regular whiteheads. So I know well ahead of time where my pimples are going to come in on my face. Is this common, or is this not acne but another skin problem? If anyone can help me on this and give me tips on how to get rid of this problem, I would greatly appreciate it (i'm 19 years old) thanks.