There's really no definitive answer for this. It could be that you have a protein in your blood that sort of trips the blood tests, or it could be in the way it was read in the lab.
If you haven't had any symptoms, I wouldn't even worry about this. Anything under a 1.10 is considered a negative. Even if yours was higher, anything under a 3.5 needs to be confirmed as it could be a false positive.