I went for an early scan today and measured 6 weeks 5 days. They have asked me to come back for another scan in 3 weeks. I was overjoyed to be told it is a viable pregnancy however I've noticed a black hole at the bottom of my ultrasound and I'm wondering what it could be, maybe it is why i have been asked to go back in 3 weeks, im not sure, they were really busy. I can't seem to find any similar scan pics other than vanishing twin examples however i feel they would have told me if that was the case. Any help to understand what it could be, would be appreciated. I will ask next time i am there but 3 weeks is a long time to overthink. Thank you in advance.