Im 25 weeks pregnant. i had intercourse on june 7th and june 28th. my due date is 3.16.14 which is my conception date?

That depends: what your estimated due date of 3.16.15 is based on. If based on the first day of your last menstrual period (LMP) and you are sure about that date or upon an ultrasound during the first trimester, that is pretty good dating criteria within 7 days. Based on a due date 3.16.15, your LMP should have been around 6.9.14 and the most likely date of conception would be between 6.18.14 and 6.23.14.

Around 6/23/14: Based on the due date that you have provided, your conception date is around 6/23/14. The due date is dependent on the last menstrual period that you provided the physician or the gestational age obtained from the ultrasound. To have a more accurate date, it would be helpful to know your last menstrual period and length of your cycles.