Well, it depends on a couple things. How long had you not seen him when you texted him that you miss him? If you saw him earlier that day or you haven't been apart for a time that's unusually long, he may have felt you're too attached and you might have annoyed him. Don't let him get tired of you, give him the space he needs to come running back to you every time. Make sure you show him the same level of interest he shows you. DO NOT by any means badger him about this... If you do this correctly he will pay more attention to you and be more open.