Hi,

I completed my urine pergnency test and it's positive. My last period was 14th April 2012. As per weeks it should be 8.1 weeks but as per USG dating scan it showing as growth as 6.1 weeks. Please suggest any further steps.

Calculating conception is always just a guess, unless you had sex only once (even then, conception can take a day or two longer than right away).
Assuming that women are usually fertile mid-cycle, then you would have conceived closer to the end of April, making 6+ weeks more probable than 8 weeks (about 2 days in April, 31 in May, and 14 in June = 47).
If your question about next steps refers to pre-natal care, please answer below.