Approximate ovulation date in your case is 24th April 2009 if you have 28 days cycle and have tendency to ovulate at mid of the cycle. As egg can live for 28 hours after ovulation, so, you conceived around this date. A sex 3-4 days before this date can also leads to pregnancy because sperms can live alive for 5-7 days inside female body with fertilizing ability for 3-4 days.
Estimated Date of Delivery would be on January 18, 2010 To come-up with this date you have to do the count down method in which you have to ( - 3 for the month, +7 for the days and +1 for the year ). Gud Luck
Last menstrual date is 29 Jan 2010