I probably had the slowest transition possible. I transited over the course of 15 or 16 years without really knowing it (or my body did, and my mind tried to catch up). Once I knew kind of what was going on, I tried to play the gender fluid role for a couple of years.
I presented as man, but every female (they seem to have far better senses in those things which are emotional) felt that i was different from other men. They told me that they could not put a finger on it, but the could talk with me and to me like to another woman, and got unexpected female type responses instead of male ones.
After a while, specifically once my breasts grew more, I could not hold back anymore, and started to come out. Still presenting as a male at that time. There more people I came out to, the more relived I felt. as if a bunch of rocks were taken off of my shoulders. At that time I started to dress female more and more, and my friends helped me (all cis women) to become a real woman!
Now that I am out to anybody I want to be out, I finally feel free.
I just discussed with my ex, what our son should call me, we did not come o a conclusion, yet!