Is it normal to have an 8 week size gestational sac and a 6 fetus?

No, it is not normal to have an 8-week size gestational sac and a 6-week fetus. Typically, the size of the gestational sac should correspond to the developmental age of the fetus. If there is a significant discrepancy between the size of the gestational sac and the size of the fetus, it could indicate an underlying medical condition or measurement error. It is recommended to consult with a healthcare professional for further evaluation and monitoring.