Hi!
I planted some seedlings in my ebb & flow two weeks ago and so far nothing has happened.
The seedlings look exactly the same as two weeks ago.

Is this normal?

I think that the roots are not yet grown, so it is growing them right now.
Don't panic, it is like same thing when you repot your plants to bigger pot, it takes a little while to plant to get used to transplant.

Ok thank you!
I will try not to worry =)