AirTag notifications pop up on my iPhone but I do have an AirTag

I keep getting air tag notifications pop up on my phone but I’ve never had an air tag, don’t know anyone with an air tag and I don’t use public transport. I just got one on my phone and it says it was first seen with me today at 8:25 which is when I first got in my car today. I wouldn’t have a stalker as I don’t talk to anyone or involved with anyone. Should I be worried? Thanks in advance.

[Re-Titled by Moderator]