I knew I was transgender since I was a 5 year old, but never understood it, took blackmarket hormones in my mid 20's, after my military contract was up, then quit due to finances and family. Started again at age 44(mental health/MD authorized), certain I would never go back, I"m going for male fail(live in a rough environment). How I hide my development, I use a widowmaker tshirt with a crewneck/vneck tshirt and a jacket at work, even when its blazing hot outside(feel I have to protect my girls) and my clothes drape over me very different now(curvy somewhat).
Did I doubt I was a tg/ts?, nope, its a gnawing feeling from way deep inside, since I was little boy that testosterone is doing its work and its just destroying my inner fabric of identity, I just denied it, it was just tearing me up, this testosterone.
The litmus test if your tg/ts is hrt, is what mental health professionals use, if your sex drive is killed, on estrogen and you fall off the hrt wagon, more than likely you may not be ts/tg.
I myself have been on hrt since late 2012(spironolactone since 2004/estrogen since 2012)and and have inner serenity now, apparent secondary development or not, I have great inner peace with myself, even against rough and tumble turmoil of my environment, but still eyeing and craving more feminization(ffs/body mods), just feel way more vulnerable now.
Will I get grs/srs/ffs? Probably will, since my body is so female wired now since being on hrt on and off since 1995.
I don't know if this answers the question, but its been my experience and readings. Sorry if I went off a tangent.