Friendly tip: it's not always helpful or realistic to compare your changes to other people's changes! Everyone, trans or not, experiences puberty differently and responds to sex hormones in their own way. The majority of transgender men (at least among those who post online about their transitions) notice voice changes within the first three or four months, but I'm sure that there are some people for whom it happens even later. There's absolutely no rational need to be concerned now — you're only a few weeks in. If it really does cause serious anxiety, though, talk it over with your doctor or therapist.