Mine was pretty low to start with, but it has changed a lot. It didn't start to change for two or three months, and it got lower in fits and starts over a year or so. It has stopped cracking now (I'm about 20 months on T), but other guys report that their voices keep getting deeper for at least another year or so, but the change is slower.
Just about everyone's voice changes -- it's one of the most reliable effects of T. According to my doctor, people's voices usually drop about an octave, so if you have a high-ish voice, it should drop into the male range, but it won't be super-low.
Also, having a male-sounding voice depends on other things than pitch: intonation, how fast you speak, not doing things like raising your voice at the end of sentences, etc. All of this is stuff you can learn, if you practice.