LDRs can work just fine, and millions of happy couples are proof of that.
Anyhow, now that we've put that nonsense aside...your boyfriend's behavior is suspicious as hell. I'd say he doesn't want people on FB to know he's in a relationship, in which case he's not really committed to you. If you're OK with that, carry on. If not, I would suggest finding someone who IS committed to you, and is proud to change their status and put up pictures of the two of you together.
"Don't say you want me,
Don't say you need me,
Don't say you love me,
It's understood..."