my feeling is you don't have to tell them now, especially if that has a chance of bringing more stormy weather
eventually, you'll move out, right? No? Now that you have a job?
chances are they won't notice any changes that you notice yourself on your body, that's the story in my case with my family, even my breasts, I can see in my sisters' eyes that for them they go almost unnoticed when I mention them... we don't see each other often but even then, no noticeable change in my face for them, I always looked a little androgynous, my hair... Looks like it's a twist of the brain where everyone who knew you before always see the same person.
well of course, there's the clothing, but... I read here stories of trans women who live stealth at their job and it generally goes unnoticed. Clothing is a big thing in getting people to notice we're trans. Now I get called Mrs on the street, but usually people apologize right after saying "Sir", so it's what I wear they first notice, and then I don't know what they notice that make them say "Sir", my voice maybe, my jaw, whatever, but transsexualism is so out of this world for them, it's not even an option they consider, so... so it'll be the same for your parents, they probably will not notice any change and they may even never admit that you are trans... but that doesn't matter since you know that you are