I know I conceived 2 weeks after my missed period which was on the 15th and I should be around 6 weeks but my Gestational age is 8 weeks what does this mean?

It means the fetus is estimated to be 8 weeks old.

Did you mean 2 weeks BEFORE your missed period? Since a missed period is an indication of pregnancy, I don't see how you could know you conceived after.

Unless you had only one sexual encounter since your last period, I'm not sure how you can know exactly when conception took place. The age of the fetus is based on external factors and is only a guesstimate.

Gestational age is counted from your last period. This is a standard way of dating a pregnancy since most women will not know exactly when conception took place. Sometimes dates will be altered slightly once you have a scan when evidence of the pregnancy is seen and possible measurements can be taken. This will give a more accurate dating of the pregnancy.

Doula gave the right answer. Gestational age is counted from the date of your last period. Even though you weren't pregnant at that time, that's when the 40 weeks begins.

So your fetus is at 6 weeks growth, but 8 weeks gestation based on your last period. Gestational age will be what they use to determine when you're due.