Hi Bozdickens,
I used to dress (still do, actually ) pretty much like you - not-gender-revealing regular jeans, large hoodie, sneakers, backpack. I thought, however, that my gender was still clearly "identifiable". I was wrong All it took me was a short haircut, and it magically changed! I couldn't believe it the first time it happened, but after that, random people identifying me as a boy became an everyday occurrence. At first I remember I honestly didn't know whether to feel embarrassed for myself or angry at them for having such black-or-white minds (I was in my teenage years and had very strong ideas about gender stereotypes and social constrictions). But at some point I started enjoying people's reactions when they realized I wasn't a boy - I'd bask in their embarrassment for a little while, just to make them feel the way they had made me feel (as stupid and downright twisted as this may sound). Until the day I realized there was no point in feeling embarrassed or ashamed or angry. If total strangers feel the irrepressible necessity to assign you to a gender, it only means they don't have anything better to do with their time