I Am 38 Weeks Pregnant And Have Tested Positive For

I am 38 weeks pregnant and have tested positive for methamphetamine usage several times throughout my pregnancy. Just today I was told the levels were high. I have taken methyldopa from the beginning of the pregnancy for chronic high blood pressure and the dosage was just increased. I do not nor have I ever done meth but I don't know how to prove it. I find it interesting that the meth increased in my system at the same time my methyldopa was increased. I'm terrified of someone taking my baby away, please help.