My little one no longer burps after each feed and I need tips! She's 9 weeks, formula fed with mam bottles, eats very well and I keep her upright after each feed for 20 minutes after to let her belly settle (while trying to burp), but after some feeds she won't burp at all. I've tried loads of different positions and can sometimes be burping her for over an hour especially during the night feed still with no result. She's burps sometimes but just not every time, she used to be easy to get burps from so I'm not sure what's changed. I'll burp her randomly through the day too to make sure she's not uncomfortable but I'm just worried about not getting it all out of her.