Hi there
You don't explain whether you want to start HRT because it seems like a good idea, or because you wish to transition and become a woman. People want feminisation for different reasons, but it rather helps to have your ideas as clear as possible, and to have a future-looking plan.
HRT produces systemic effects, both physical and psychological, so have you considered the mental and emotional aspects? Those could easily be more noticeable to people than little breasts.
I think it's important to start HRT understanding clearly what possible effects they may have on you, but also to keep your expectations realistic and to not obsess about the possible results. I've seen people on this site express extreme disappointment about their HRT results, hoping for big breasts, hips and whatever else, and some bodies just don't cooperate.
Good luck
J
