When to discuss what's in your pants?

Odd title, yes. But all will become clear. First, a little background.I am female to male transgender and I identify as being gay. It took me a very long time to figure out I am trans (I recently turned 30) because of being attracted to men. There wasn't as much information out there when I was a teenager compared to now. In fact there was a lot of misinformation. Due to these reasons, I stayed in the closet.I don't really date or have sex, haven't done in years as I plan to transition (I finally get testosterone in October! Very relieved.) and the men currently in my life are either straight or gay (not a bisexual among them). It is very unlikely that a straight man would stay with me during my transition, and a gay man would not be attracted to me as I am now.Having read through a few threads on reddit, I have learned that there are gay men who would be willing to date a transman, which is very reassuring. But...At what point do I tell my date that I am trans?Having asked my irl friends, most of them said that they'd want to know straight away. Three of them said that the reason for this was because they wouldn't want to date someone with a vagina. So knowing upfront would mean that they could cancel the date. Two of them said they'd want to know straight away because otherwise it is lying and they wouldn't want a relationship based on a lie. One of them said he didn't mind either way.Being told it felt like lying makes me feel rather uncomfortable. As does the thought of telling someone about my trans status straight away. Not very romantic really. "Hi! My name's Gabriel. By the way I have a vagina."Now... Six gay men isn't really a good pool of information. So I am asking you fine gentleman your opinion.When to discuss what's in your pants?