as per the details u have given,
the emergency contraceptive
pills contains high dose of progestins mainly levonorgestral, these emergency contraceptive pills work better when they would be taken with in 72 hrs of unprotected intercourse
..okay.. so for the first time of unprotested sex u took the pill immediatley so it works... and after 1 week u got periods known as withdrawl bleeding..
now again u had unprotected intercourse, here come the problem ..becoz , these emergency contraceptive pills has no role in protecting u from prgnenecy if u didnt take them with in 3 days.. so you do have the chances of pregnecy.
so if the implantation
doesnt occur u will get periods with in 16 th of march ..or else so i advise you to get the urine for pregnency after 16th of march and confirm it...