Does masturbation affect size?

Now before reading this know that I'm not another teenager who's worried about having a small thing, I'm perfectly comfortable with my size and even if it were below average I wouldn't care, so I'm asking this question out of pure curiousity: Whenever I go like a week without masturbating (which probably happens about twice a year at most) my is about 1/2 inch larger when I get a ***** than it is on days where I've jacked off recently (within the past 3 or so days). This has to mean that masturbating does affect your size, right? Or is this just me?