Hello,
It is seen that pregnancy only occurs if intercourse occurs within the 6 days prior to and including
ovulation. The best timing of intercourse in order to conceive is day 10, 12, 14 and 16 (in case of late
ovulation) of a 28 day cycle.So if you had last menstrual period on 15th sep 2008 then ovulation would have
been around 28-29 sep and in case you had irregular periods,so it could have been on 1-2nd nov.So you could
have conceived on any of these days after unprotected intercourse.Best..