What is this yellow flower/weed?

I have recently been trying to grow marigolds from seed, and as it grew I noticed the stem and leaves were not at all like the adult stem and leaves but maintained the hope that it was just immature and would change, but today it flowered into a very small yellow flower with little rods inside the petals and the stem is green with a creeping red that just started showing and long thin smooth oval leaves on a single stock. It is in a pot in my screened in pool area so I had hoped no weeds would get in, but now I am unsure. I got the seed from a little ceramic egg I got from Lowes but I broke the egg and planted it in garden soil I bought that same day and I live in central Florida if that helps.