Feeling heartbeat, is that possible?

Okay, I know this sounds crazy 😋 But these past few weeks I've began noticing that when I'm laying down on my back watching tv, that I am feeling a heartbeat sensation from my abdomen? -But not from holding my stomach, like i notice it IN my stomach, not looking or feeling for it. I haven't heard anyone else experiencing that?? And yes, there is no need for lectures, I am well aware of not sleeping on my back lol