Why havn't I hear from this guy after I wrote?

I'm so attracted to this guy and he likes me too. Up until now we've been friends..we knew each other a little before he moved to another state. Since then have kept in contact by chat..once a mth or so. Now I have to visit his city for work and he'd love to meet up. Problem is I'm already so into him and can't stop obsessing. He wrote that he's going to fall in love with me. Also said hurry up and come visit. Thing is I don't know him that well..but I do know he's attracted to me & seems like a decent guy. I'm just worried as we don't chat very often. Now its a few wks since we've chatted..usually he contacts me. It's making me insecure & worried but I do know he's really busy now and the last contact (by him) he checked again when I was leaving! I recently mailed him to tell him the date I'll be there and am waiting a reply. That's more than a week ago. Why hasn't he got back to me?