I like this boy very much?

I don't know if this is the right place to ask, but there's this guy and I really like him. I used to see him quite allot on the bus last year, but I was always to scared to approach him. I saw him again yesterday, and I found the courage to talk to him. He was very nice, and I was immediatly in love. After asking his name, I added him on Facebook. So Facebook is the only contact we have at this moment. I know he doesn't live far away from me. I send him a message yesterday and he replied but now he didn't reply anymore and I don't want to send another message I mean, I don't want to annoy him or anything. What should I do?