Hormones from last pregnancy or a new pregnancy?

Jamie

Does anyone know how long the hormones last in the body? My daughter is almost 8 weeks old and I took a pregnancy test as a joke and there is a faint line...I never started my period but know you can still get pregnant. I had been taking the mini pill and we still used a condom but I'm kinda freaking out right now. Could it just be left over hormones from my daughter or is this a new pregnancy?