Gonna add another check mark to the "things can happen quick, even on low dose" column.
I started on low, low dose - like the lowest dose humanly possible to obtain - and within days it was sore nipple time, and a couple of weeks before I could feel a significant hardening beneath. Mental effects were instant - loved the sense of calm.
Enjoy it! Those early changes are exciting. Now I'm on a much higher dose, things are moving along, but it's not quite the same as first discovering that this is actually happening.