Some advice needed on boys...?

basically, for the last week or so i've been having a pretty intense friendship with this guy i don't particularly know that well. it's mostly been through texting and facebook and i've really only spoken to him face to face once. it's clear that we have an interest in each other because there is a lot of flirting going on. he's lovely and very charming. however, for the past three days it's fizzled out and its a bit disappointing because i would really like to get to know him better and i'm worried i've scared him off. its almost seems like he is avoiding me. should i lay off for a while, do the whole advance/retreat thing? pretend like i'm not that bothered that he doesn't talk to me very often now? i'm thinking that it started off too full-on and now i think he's a bit scared that i'm the clingy/needy type, which i'm definitely not and super worried about. help??