Most Helpful Guy
It may mean that he doesn't care very much about you, but that would be a harsh judgment to make and an evaluation such as that should be based on everything you know about him and not just how he handled your birthday.
It may also men that you are insecure in the relationship and rely too much on tangible expressions of his devotion rather than trusting what he tells you about his feelings for you. Only you can decide whether this possibility rings true for you.
Most Helpful Girl
You're not sad at all you're hurt, that's a strong emotion it takes time to heal from unless you go to your boyfriend and talk with him about it.
You're right in feeling the way you do but as I said you'll carry that hurt feeling with you the entire time you're together.
The only thing and I mean the only thing you can do is look him in the eyes and express your hurt.
Don't text it that won't have the same effect.