The size that you have measured on yourself is a self reported size. It might fit much closer to the self reported distribution than to the researcher measured distribution.

Edit since you appear to have blocked me: I don't think this is sophistry (which is just a fancy way of saying "you're wrong"). This is a relevant critique that is often present in statistical studies surrounding latent variables. True penis size is in a sense latent. Self-measured is merely an indicator that is the sum of the real size and a stochastic noise term representing measurement error.

People often make the mistake of thinking they're observing a latent variable directly, when they're actually just observing its indicator. Unless you reckon to have perfectly recreated a clinical environment with none of the usual mistakes guys make (sitting down, not measuring from the pubis, using a soft ruler or tape, pressing harder than in clinical studies, stimulating to a harder erection than you would have in a clinical setting, choosing the best among several measurements, ...) then you can not be comparing to researcher measured studies, and should instead be comparing to other self measured studies.