Why hasn't he messaged back?

So I kept seeing this guy around school all the time and I was on my best guy friends profile and saw the guy on his friends list so I added him. He accepted and then 2 days later I messaged and said "Oh hey" and he wrote "whats up?" and I wrote "Oh nothing much. Just SO glad spring break is here." and he wrote "Oh yeah me too I'm in San Fran (:, where do I know you from?" and then I wrote "I see/saw you around school!" This was 2 nights ago and still no response... so um lolwut now?