Ya know, my thinking is that ok maybe it's not picking up HCG but that doesn't necessarily mean that SOMETHING going on in your body when you're very early in pg is not causing this positive result to happen. Doctors really know very little about the complex communications within our bodies and it is not a reach to me to think that the fertilized egg may communicate with the ovary in some way and that this could be something an OPK can detect. Who knows???