Looks like a zinnia?

That was my thought, but I could have sworn it was something else. Or maybe it is a zinnia and I got the pot mixed up with whatever the other plant was.

I had something similar happen to me. I bought a package that had a variety of wildflowers in it. I loved the "little pink flowers" that came up so I decided to save seed from them. I have no idea what they are but they'll be back in my garden again, and I figure at some point I can ID them. They don't look quite like yours.

There's many different kinds of zinnias, with different flower forms, somewhat different leaf shapes, heights from 6 to 8" tall to 3-4' tall or taller, and even different petal shapes. There's also an amazing range of colors. If you let your zinnias reseed annually and they cross-pollinate, you can get even crazier-looking ones. Do the leaves look like a typical zinnia shape?