Two points:
To the original OP it's tempting to say if you have concerns, just wait. But honestly, if you do that, you'll never find the perfect time to begin. After I made my appt to start hormones, I was assigned a one week out-of-town training assignment--as the trainer. I thought about waiting, but I've been waiting for 40+ years. It was time.
As for women reacting differently at work, I've noticed that too, but I had just started working there a few months before starting HRT so I don't know if it's just getting to know me, the hormones, or both, but it is a different relationship. And it is nice to hang around the other gals without having to act all manly and such--just to be myself. I even have a Wine and Cheese Shop buddy I go to the local wine merchant with almost every pay day.
Jane