Hello, I am a 16 year old trans girl. I was wondering if the having orgasm,s affected the testosterone levels in your blood. I masturbate only because I heard somewhere at the very beginning of my realization of being trans that it helps for SRS. I'm not sure how that does though. My testosterone levels I assume are pretty low since I usually have next-to-no sexual urges whatsoever. Will they affect me negatively? 
I have been on the anti-androgen Lupron for almost on a year now.

Regular masturbation really any regular sexual conduct will increase your testosterone levels it's not a lot but it dose go up. Before starting hrt, I engaged in solo fun time often very often like really really often :-) not really ashamed just a fact. Despite that turns out my Testosterone levels where still low. Now the hrt has decreased my sex drive and I only love myself very often :-)

As for it helping with the surgery regularly exercising the flesh can keep it stretched and make things easier on the surgeon, further the odds of being capable of orgasm post surgery are better if you regularly did so before hand.

Serena, Fairy queen of TMI

There is a spot between the scrotum and the anus, the perineum which can be gently pressed right before an ejaculation.
This is an old technique to kind of keep the energy in and it might help keeping in a flush of testo released in those moments.
Don't press too hard...
you might give it a try...