I had sex on the 20 oktober 2010 . On the 10 November 2010 I got my period ,it was heavy to normal and lasted 6 days. After my period I had sex again on several days.it is now the 07 January 2011 and I am 8 weeks pregnant... when dit I got pregnant? Before or after my period?

Odds are far greater that you got pregnant after 10 November. Your pregnancy would be farther along if you became pregnant from the sex on 20 October, and you had a normal period after that.

Once you have a scan, they will be able to determine if you are farther along than the current dates going from your last menstrual period.