so my doctor gave me the due date for November 9th the ultrasound says I'm measuring 26 weeks and that my last menstrual period was January 15th. The problem with that is I know FOR SURE that my period was on Christmas and ended on January 2nd but they don't believe me. I'm scared that my baby isn't growing right because if she was then I'd be measuring around 28/29 weeks right now. Please help