My 3 week old won’t burp at all after feeds now! She was ok for a while, then it started getting tricky, now nothing at all! I can be doing it for nearly an hour and nothing, in every way possible, sitting up, over the shoulder and knee. I keep her upright for about an hour after eating, she doesn’t seem to bothered, she doesn’t cry, doesn’t seem uncomfortable. Will it be doing her any harm if nothing comes out??