My doctor said I got pregnant in aug on the 20 my period last period came on Aug 20th may have been implantion I think , because sep I didn't have a period I ovulated on Aug 1 I Had Sex Before And After ! Then i had sex the end of aug with some one else but Some people saying I got pregnant in sep ?? How did I ? If I was already pregnant in aug on the 20th ?? Help ! I'm due may 27 and today I'm 18 weeks and 3 days today is dec 26