I started actively presenting as male at work six and a half weeks after my first shot. My voice was changing but clearly wasn't masculine yet. I had not had top surgery, but I was binding every day. I've always worn male clothing at work, I've always had the male name at work, and I've always gone by "Mr." at work. All the same, some of my students called me "he" and some called me "she."
I had spoken to the HR person several weeks before, and I crafted an announcement that she sent around to the entire department. I started using the unisex bathrooms in my building. I didn't want to use the men's room until I was clearly "passing."
I felt a little weird about being in the "ambiguous gender zone," but that only lasted for spring quarter. Over the summer I masculinized even more, had top surgery, and changed my docs. Now I use the mens' room at work, and my students uniformly call me "he."