Just saw something similar looking in the forums here. Is this verbena?

Yes, Verbena bonariensis.

Thank you so much. I wonder where it came from!

I grew some verbena bonariensis once just for fun. That was four years ago. Every year there is still a healthy crop of new seedlings... Keep in mind that I have pulled them all before flowering since that first year. The seeds last forever and they travel by wind pretty well. So a neighbor could have had one 5 years ago and now you have some.

Wow thanks! I think that's what happened. It planted itself in a pretty OK spot so hopefully it stays around there.