In the New Moon script, Jacob is in the parking lot. He meets Bella and Edward. He gives her a birthday present. It happens to be a dreamcatcher necklace.
Now, the bracelet, and I'm assuming you're talking about the wolf bracelet, isn't gegeven to Bella until Eclipse. For her graduation. So, NO WORRIES!
I can't guarantee that the bracelet will be in Eclipse since I don't have the script yet, but it's not in the New Moon movie because it wasn't in the book! :)
And, I'm sure they will include the charm bracelet in Eclipse. That's one of the pinnacle points in the the book. And Summit isn't that stupid to leave that out.
They should have left it a bracelet, it's meer discrete. Bella is not the kind of girl that likes to toon off and a halsketting, ketting is meer obvious than a bracelet. Not to mention the diamond.
I think it's kind of silly. It's so easy to just follow the book, but they just have to change the little things. I don't understan why they wouldn't just stay as true to the book as posible.