At a glance, it looks like Jimson Weed to me, something from the Datura family. As already mentioned, it's hard to know for sure until it matures, but that would be my guess. My brother has it as an ornamental "moon flower" in his front yard, and a slightly different variety has been growing wild in my parents field for decades. I'm not an expert, but that's what it looks like to me.
It's in the nightshade family but it's not an eggplant for sure. It might have little black stickers that stick to you, but then again the black stickers might be from another plant. So many weeds, so little time.
I'll try and get an adult photo this year.
Alternatives... perhaps cocklebur (Xanthium). Would explain the stickers, seeds in a small oblong pod with bristles, two seeds, one germinates the next year the other dormant, plant very aromatic( I can't describe smells!). Another possibility, False ragweed (Iva).