So confused, help?!!

Jade
For the past week, I've been taken pregancy tests. 3 have came out positive (faint lines) & 2 have been negative. 
The 3 positive I done in the evening and the 2 negatives in the morning.. Now before bed I have to take centain medication, could my medication be interfering?? As the positives are done when my body is clean from any medication. 
I'm due on today and no sign of my period.