Headspin, NO, NO, NO, it is normally 5. Gestational age is fetal age + 2 weeks. The doctors normally gives gestational age, not fetal age.
That is why a woman is 40 weeks pregnant when she is due, even though the baby is only 38 weeks old.
So if the doctor said the age is 7 weeks, the baby was conceived 5 weeks earlier from sex between about 5 days before that date to a day after.