I really need help with my situation. I had unprotected sex with my boyfriend on September 7,8,9 2007, I had what that I thought was a period on September 16,2007.Then I had sex again on September 23,28-30,2007 the midwife gave me September 24,2007 as my conception date,I am now 23 weeks pregnant(found out I was 7 weeks pregnant on November 6,2007) Ultrasound on January 16,2008 said I was 18 weeks preg, When did I have sex to conceive on September 24,2007?