7 weeks 2 days.. no baby but a sac

So I previously posted I didnt want to go in for  an ultrasound this early but I did anyways and all they saw was a gestational sac. no baby. no yolk sac. nothing. I am so hurt and thinking that I am going to have a miscarriage and how stupid I was for telling friends and family. The ultrasound tech couldnt have been more rude either. She did an abdominal us and a trans and both looked the same It is possible that my dates are off but I found out I was preggo aug 30th and my LMP was July 29th. I dunno. I am just so sad.