6 weeks 1 day ultrasound with just a sac

Hus

I went to my ultrasound appointment at 6 weeks 1 day gestation.The technician did the ultrasound on the abdominal and transvaginal, she said that she could only see the sac which was growing and in the perfect place but no fetal pole or yolk sac. I am very confused I don’t know whether to be happy or not. My last period was on the 2nd of November and I ovulated on the 20th of November, the ultrasound was done on the 15th December.

Please give me some advice I am very scared. I also have had 2 previous miscarriages. I also have pcos.