2 millimeter blood sac near baby

So I went to my obgyn today and found out that I’m 9 weeks and 1 day. She also informed me that I’m not high risk but there is a 2 millimeter sac of blood next to the baby. It was hard to hear her cause I had my 10 month old with me and she was screaming her head off.. but she said that the sac of blood could cause a miscarriage. I’m scared to death cause I know mentally emotionally and physically I could not hand a miscarriage. I was wondering if anyone else has ever had this and went on to have a healthy normal pregnancy?