6 week scan

My 6 weeks scan only see sac from my eyes.. but doctor did not say anything and ask me to come again on my 11 week..should I feel worry? Dont know why Im so stucked with blighted ovum pregnancy in my head. Should i keep calm and go scan at 11 weeks, or should I go for another scan next week? Plus how 6 weeks scan suppose to look? Mine dont have smaller dot inside the seen sac.