You said 'planted', not 'started'; I assume you meant in ground? It is way too early to plant zinnia. I never really understand what to do with poppies, but I assumed they were best started in fall, but late winter probably works. I think that they are 3 week to germination. I read that echinacea is to be planted before last frost, but that would also normally be three weeks from now. I think germination is also three weeks.

Its a bit early to start worrying. Most seeds need a required amount of time, moisture and cool weather to sprout. For some of the plants on your list it is easiest to just scatter them in the fall and let winter help you with the chilling and moisture part of it. Some seeds need darkness (being buried in the soil) while others need light to sprout. With this cold weather it may be a while before you see sprouts.