Hi Rosa
I tested with Lullaby this month and didnt get a very dark Test Line, it wasnt even close to the Control Line.
I did test towards my O and just noticed it from nothing to very faint, to faint. then very faint to nothing again. I had EWCM the day it was darkest (but still not close to Control Line)
So, I think I'm one of them who never gets a real dark line even with something as senstive as LC. I tried other brands like Ovuplan and Discover, there was almost nothing at all. Very very very faint. So the darkest i ever got was w/ LC
hope this helps!