Ask Mr. Smarty Plants

See, the thing about native wildflowers is that they have adapted, over millennia, to the conditions in which they grow. You planted your seeds, probably watered them, and they thought "Yippee, water" and up they popped. Maybe a few of them will be damaged or killed by cold weather, but most of them will hunker down in the soil and come up later when the sun is out. Bluebonnets, for example, are considered cold weather annuals. They normally start coming up pretty early, have a low to the ground rosette, protected from the cold by the warmth of the earth, and develop roots so they will be ready to start blooming in mid-March. You should always plant a lot more seeds than you think you have room for in your space. Some of them will come up too early and die, others will wait out the cold weather and come up at a good time, some of them will wait in the soil, even for years, for better conditions and some of them will never come up at all.

Oh, and by the way, you should keep an eye on those seedlings. They may be weeds that have just been waiting for the right moment to make their appearance.