Question about exclusivity in a new relationship

I've been seeing a guy for the past couple of months. Things are going great.  We talk about the future and we are really into each other.  I'm wondering when is a right time to bring up the idea of us being "official" or "exclusive."  We do couple things, we talk all the time, we spend a lot of time together.  Does this mean we're a couple or do we have to have that talk? I'm not sure if and when it is appropriate to bring it up or If I should even bring it up in the first place.  I don't want to scare him away but maybe there's the idea that we won't even need to talk about that because it's alright going where we both want it to go.