Our last average frost date in 7b is april 15, so I would just wait another 2 wks. Harden them off by taking them outside and exposing them to more cold temps and sun if you haven't started that already.

Around May last year, after finally getting some plants into the yard, I got some cutworms in my garden area. Never had seen them before or experienced it. They were there for about 1 month before they matured and took off (I guess -- unless I managed to kill or control them, or the plants got bigger)

So protect those seedlings, especially if they are still as small as what you describe.

You'll have to learn to recognize some of your seedlings, especially if some of them self-sow. Next year, you'll have to contend with weed seedlings and your perennial seedlings in the same area.

But I think your timing will be fine. Many people will just be planting directly to the soil in a few weeks and those seedlings also survive just fine. In fact, some of my unfortunate luck with transplanting seedlings is that I don't transplant correctly. That probably kills more seedlings than sun or rain at the beginning.

When planting something small, I like to make a ring of rocks around it. That also helps stop squirrels or toads from digging around in the now-soft dirt there.

Anything that you will notice will do, a bamboo skewer, popsicle stick, old mini blind slats are easy to cut into plant markers (and write on,) even a stick that fell off of a tree. Sticking straight up, definitely a reminder. Styro produce trays are easy to cut, you could make little 'collars' if you don't like the idea of something sticking up. 'Rings' cut from a TP or paper towel roll might also work (and will just decompose.)

Wildflower seeds germinate at different times and grow are different rates.

Some won't hardly even germinate without being cold for a period of time while others don't care.