OP, you say you're new to the company? They probably have a roster with people's birthdays on it, and you didn't make it on this year because you're new.
It's very nice that you're thoughtful and think of others, but many people aren't like that. Some may have also felt weird, because they don't really know you yet.
I'm sorry your feelings were hurt. I hope next year the people at your company remember and do something nice for you.
Happy belated. Here's a cake for you.