Why did I hear a purchase chime without buying anything on my iPad?

I was playing a game on my iPad and all of the sudden I heard the chime that goes off when you make a purchase in the app store. I have not downloaded anything or purchased anything or even opened the app store. No purchase screen came up for any in store purchases, and even if it did, it would’ve asked for a fingerprint confirmation and it didn’t, and i wasn’t holding my finger on the power button either. Should I be concerned?

[Re-Titled by Moderator]