I am taking a b12/hcg shot for weight loss the shot I am taking only has 125ui of hcg and I had my last shot 6 days ago. I missed my period yesterday so I took a hpt (first response) today and got a positive so I am wondering if with the low dosage of hcg that I had if it could still be in my system giving me a false positve or if it would be out of my system by now and I could be pregnant?