That's completely normal.
About a 1-2 months after I started taking finasteride, I experienced more shedding, and the hair falling out was the thinner miniaturized strands.
6-12 months later the thinning areas had completely filled in, and 12-18 months later I'm seeing some regrowth on my temples as well.
Just hang in there and don't worry about it, because in time you won't have to.