Hey! my lmp was aug 13, 2015 and my period is irregular but now i"m pregnant. how can i figure out when my due date and when did i conceive?

Not straightforward.: If your periods are irregular, you will use your LMP as the last objective milestone. Conception would be two or three weeks later if you are regular. An ultrasound will give you another point of reference. It will be an estimate. In the end the people who know the actual date of conception are having in vitro fertilization. Best of luck to you.