Congrats on starting T!
I just did my 5th shot yesterday and I've had two periods since starting. Generally speaking, except for some lucky guys, shark week doesn't stop immediately. It's something that happens over time. As powerful as hormones are they don't change things overnight, or in a few weeks, and we're talking about a whole SYSTEM inside your body that needs to be shut down.
I was told that my periods might change before they disappear completely - get heavier, lighter, spotty, etc. Since everybody is different, there is no way to tell WHAT will happen - or WHEN. I'm just happy that my PMS/PMDD stomach issues are pretty much clearing up, slowly but surely.
At this point, i would say focus on working with your doctor to make sure your levels are where they need to be. Your body will take care of everything else with time. Don't be discouraged if things don't happen right away, or when you hope they will. They'll happen.
As a side note: if you think about it, when women are given birth control they are told (depending on what form it is) that their periods will likely stop. Doesn't always happen right away for them, either. It could take a cycle or two (or three.)
Congrats, again! Good luck!