I wouldnt feel bad about it. In my before time when i didn't understand my own personal trans issues were and I worked in food service I would occasionally encounter someone who gave me mixed gender signals (it was a pizza joint so we phone calls then pick ups) When i was conscious of what was happening I would avoid using sir and ma'am if could not nail down the voice, that way i did not do anything to embarrass them. Of course, if you have ever worked in food, its brutal and soul sucking, so after a long day your brain could be on auto-pilot so you will pretty much respond to the first key thing you hear. So even if the person heard your voice and were confused upon seeing you, im sure they probably didnt even notice since they had 100 more orders and screaming children behind them! So don't take it personal, and as everyone else says, simply go about your business. When i was younger and hadn't even began to acknowledge with my own dysphoria issues I would be mistaken for a girl on the phone (and to this day i still do not know why) at the restaurant. That would certainly anger me, and in a way that it would take years to fully understand why. Its odd, when you want to be treated one way, you get the opposite, and when you change to the way you were being acknowledged, it all changes back! Such is life i guess, so as long as you are happy I say do not be discouraged!
