Baby size and Menstrual cycle

Maybe the ovulation is later hence conception is later. When I went for my first appt, I was suppose to be 6 week too but doc measured as 5 w 3 days. 1 month later, measure 11 weeks 1 day so a few days difference only from when I count using lmp. Not to worry. Sometimes the baby is too small to measure they can only estimate how old the baby is. Wait for your 2nd appt for a clearer pic and edd!