Ever since I was fourteen no one believed I was gay. I guess at fourteen that problem makes sense. I'm just getting really pissed off because I'm now twenty. I still have the exact problem I had when I was fourteen. Everyone tells me they think I'm bi or I just don't come across as gay. This is generally with people who know what I look like. I don't think I'm that girly. I think I'm very average for a girl. Even I have trouble believing I'm gay because of OCD symptoms.
I have this problem too. Less so now that I'm older, but I heard it all the time when I was young. I know most people aren't trying to be insulting, but it's pretty offensive. If you can be bothered engaging with them, I find that the best way to deal with people like that is to keep asking them questions until they realise for themselves that they're being silly. For example: "You don't look like a lesbian." "What makes you say that?" "Well, uhh... you're feminine and just look normal." "What makes you think lesbians can't be feminine or look 'normal'?" And so on. I find that most people back themselves into a corner pretty quickly and end up apologising. Other people are just determined to be ignorant no matter what, in which case it's best to just ignore them.
My wife had two girlfriends who said they were lesbians. They were very feminine. Cute, sexy, beautifully dressed. Mary says there is no lesbian fashion. The problem lies in your friends. The guys just want to get you into bed. Isn't it weird how people want to tell you what you are? Mary is bisexual, and people like to tell her she is lesbian. Oh well. People just want to be contrary.
I always had the opposite problem. From about the age of 18 onwards I've always had short hair, I have a slim figure and a preference for boys/mens clothing. And apart from the odd occasion when I've been mistaken for a biological guy; because I like women everyone thought I was a lesbian and I guess I went along with it. I now know my true identity and feel much better about myself than I have in a long time. There is no rule book for how to be a certain gender or sexuality. If they can't accept who you are it is their problem. You know your truth.
I would come at this from another angle. Why are you trying to convince people you are gay? I've been out for twenty-five years and I've told exactly two people I was gay, my parents. Even my siblings just sort of found out. People find out because I go to gay events, back when I dated I dated men, I've been known to think the UPS guy was attractive, I'm married to a man. People are generally surprised because I don't really look gay (whatever that means). But I don't think anyone would think to disagree, mainly because even if I'm the one doing the talking I didn't tell them I was gay, they found out.
Yep, I think you understand the situation. And yes again, you're completely justified. Just because you don't "strike a pose" doesn't mean you're plain vanilla. (With apologies to vanilla, which I actually adore.) I think you have gotten good advice from above posters. Good luck!