3 w/o not burping...

My daughter is 3 weeks old and I cannot get her to burp to save my life! There's times she will no problem, then there's times where I'm changing positions, moving her, keeping her awake, just for trying to burp her for a good 45 minutes to an hour. And NOTHING! Is anyone else's baby doing this? I feel like if I don't get a burp out of her she'll always end up with a tummy ache... 😢 Help? -FTM