Anti S abnormal

Hope
Hi I'm just 12 wks today! Just got a call from my ob office that I'm going to be needing to see a Maternal Fetal Medicine specialist because one of my blood tests came back abnormal. She called it the Anti S antibody. Anyone have any experience with this? I can't find much on it online. They are to call later today for our appointment with the specialist. He will be over 2 hrs away from us. Any support or advice would greatly help me! Thank!!