A pregnancy age's is counted from the first day of the last menstruation (the 2nd of July 2006 in your case).... not from the date of conception. Conception happens several hours after ovulation, which itself occurs about 14 days before the next period is due to arrive. If your menstrual cycle usually lasts 30 days and your last period started on the 2nd of July, then ovulation (and conception) probably occurred around the 18th of July, 2006. Two days before and two days after the ovulation date are considered the fertile days of your cycle, which mean any unprotected sexual intercourse between the 16th and 20th of July 2006 could have caused conception.