It's easy to do when you don't know what the seedlings are supposed to look like. I grow lots of weeds that way.
Biggest thing is to be patient. I think it was probably about May before I put mine out but I can't remember for sure. I have grown them for several years then skipped a year. I did have others over winter for me as well then died the following winter.
I grow mine for selling bouquets at market. I pinch the center when they get larger so they produce more branching flowers. They are very pretty and worth the time. If you're lucky, you may get some to go to seed as well and you can collect it. VERY TINY seeds as you found out.
