Odd vibrating sensation in chest. Should I be concerned?

So I had top surgery on Tuesday. This morning, I’ve noticed a strange sensation that happens from time to time. On the left side of my chest, near my armpit, on the front but feeling like it’s coming from under the skin, it feels like there’s a slight vibrating sensation. It’s like someone placed a small vibrating object on my chest. The sensation isn’t in my whole chest, just in a small area about an inch or so in diameter. It doesn’t last long (never longer than three-ish seconds) and it isn’t painful. My drain seems securely fastened, and I don’t feel any leaking.

So I’m wondering what this is and if I should be concerned. My current theory is that I’m just feeling fluid getting drawn into the drain. But I thought I’d ask in case it’s something serious.