Q:

My last LMP date was - 22 march 2016. could you please tell me my expected delivery date



Due date - is the date that spontaneous onset of labor is expected to occur. Its an estimated date calculated by adding 280days (9 months and 7 days ) to the first day of the last menstrual period.
So according to that, it will be 29th Dec.

Congratulations and happy Pregnancy

Quick Tip - your sonographies will keep showing different dates but at the end of all, follow the due date by LMP.