Weird heart flutters

Ta

So for a few years I’ve noticed that sometimes my heart feels like it has stopped for a .1 second and I have to take a deep breath and then burp or something cause it’s caused by an air bubble or something. I’ve been to heart doctors before and they’ve monitored me for 48 hours and they said my heart is healthy. Just wondering if anyone else has felt like this before? I’m 26 weeks pregnant and since being pregnant and having heartburn it happens a lot more. But it’s so weird that I have to burp to make it go away pretty much. It’s like a trapped bubble by my heart causing palpitations.