Why do doctors add 2 weeks to pregnancy? my lmp was 8/23/14 but i know i conceived on or around 9/6/14. how far along does that make me today 9/17/14?

It's just a standard: To keep everyone in the country talking the same dates, a pregnancy (in weeks) is counted from 2 weeks before conception. So, the start date is about when the last menstrual period began. How far along a woman is today, is just the number of days or weeks counting from her LMP of 8/23/14. The looks like three and a half weeks.

Back date to LMP: Doctors count from the first day of your last menstrual period,so at conception,it is estimated that you are already 2 weeks pregnant. you are 3weeks and 4days pregnant on 9/17/2014