when should pregnant women have first scan?

Usually before the 12th week of gestation, that is the most acurate one.

By the 6th week of pregnancy

17 - 18 weeks

i think 8wks into the pregnance is idle

I'm thinking it's about 14-20 weeks into the pregnancy. Might be earlier if the doc is worried about development or the lady has a prior history of problems.

2 month?