I started HRT about 13 months ago. I also started wearing women's clothing full time shortly after that. Fairly quickly, the number of people calling me "sir" dropped, and there was a long period where aside from the occasional "ma'am" or "miss", people mostly just awkwardly avoided using any prnouns with me. Then at about 6 months, the number of people calling me "ma'am" or less frequently, "miss" went up and up. Now, I don't remember the last time someone called me "sir" unless it was on the phone, and people call me "ma'am" very frequently.
I want to believe that this is happening because I'm passing, but doubts keep creeping into my mind. I dress very femininely, and I wear makeup every day. I often discount being gendered correctly as "people just being trans friendly and polite". My voice is still fairly deep, and if I'm on the phone, there's still a pretty good chance of me being called "sir". I'm especially baffled by cases where people use female pronouns with in person me after I talk, because I'm not that confident in my voice yet. What I'm wondering is: how often do people notice that someone is dressing as a woman, and just use female pronouns with them to make them feel better?