It could absolutely be wrong. Baby is so tiny at 6 weeks could be easily missed or incorrect weeks. Relax mama and just wait for the results at a 2nd scan
My friend thought she was having one baby and then at the 6 month mark she found out she was having twins
My friend discovered twins via a scan at around 28 weeks… the 2nd twin had always been hiding behind the other one. 🫣
I was pregnant the same time as my coworker and she went half of her pregnancy told it was only one just to find out she was having twins