Anyone use a life brand pregnancy test and get a false negative?

I don't know if there's a difference between a negative and a false negative but if it is can you tell me. I am 4 days late and I realized two days ago that I was and no sign of my period,lots of discharge,migraines, I'm always tired and feeling a little nauseous. I took the life brand test and the first line was dark blue but the second part where you get a positive or negative sign was a light blue