Your LMP was 25/3/2012.So EDD is 01/01/2013 by just adding 9 months 7 days+LMP.
Currently you are carrying 39 wk+ pregnancy
by date and recent USG report reveals 36 wk plus fetus maturity. It may vary to earlier report due to late scan maturity.
By date you may wait for 2 wk i.e up to 42 wk (Term Pregnancy) with weekly check up and clinical assessment. And by this time,if your labor pain
does not start,then need some intervention as it is called post term pregnancy. In this case,caesarean section
is best choice.
So don't be much worried.Just do regular check up and feel fetal movement