At what point do you follow up?

If the hiring manage tells you that they are just at the beginning of their interview process and they will be in touch. Do you follow up at all if you haven't heard anything and if so how long do you wait?
I just don't want to seem disinterested but I don't want to be a pest either.

At what point do you follow up?

I usually do within a week or so if they don't specify a time. Did you send a thank you? I would email one when I got home then mail one if I really wanted the job that night or the next day. I would then send a follow up email within a week if I did not hear anything.