should be three months but no baby found

Jennifer • Angel baby in my heart 27/01/017 married 01/03 rainbow baby in way EDD 15/12/2018
Been told to go back in two weeks for scan but one today showed a sac but no baby and the sac was a distorted shape. She said i must be earlier than i think but my last period was the 16th November and not had one since
I have no idea what to think
I did have a red stripe of blood yeserday but they said it was normal not enough to caause worry
But i am worried