I don't understand

Stefanie • I`m 28 years old and happily married and have 4 children. 3 girls and a newborn boy!
So I don't know if I'm just seeing things or not. AF is supposed to come today. However I feel like I'm getting faint lines on my tests but they don't get darker. And the "faint line" shows up immediately. I've takin other tests as well and it's the same. I've also been spotting brown for the past week or two on and off. I had a chemical in October, my first one. I just don't know if these tests are just wrong or what. 
Are these just really negatives?