what is going on with my stomach

Hello everyone who reads this 😆. So I am ill at the moment and I was laying down on my bed with my phone on my stomach and it was moving. I took it off and had a look at my stomach to realise it was beating, pulsing almost. This kinda freaked me out. But I checked my heartbeat and it was in time to my heartbeat/pulse. I found this pretty weird so I wanted to get some answers so I went on some medical websites and some said it could be abdominal aortic aneurysm. I don't normally believe Google but I had to ask you guys. Any ideas what it could be?