Welcome to HCM,
After going through your history,you were exposed to unprotected sex on 10 th march wich is 13/14 days prior to your dates which the time of ovulation, you took I pill
in 3 hours this is emergency contraceptive pill
with very good success, but remember this is not 100%.
Hence by this time you should have started your period, now what you can do is to test urine for pregnancy
,if it is positive then you are pregnant,if it is negative then you can wait for your period to come for a week,if period comes then it is fine other wise repeat urine test.
Your health is more important so please visit a good Gynaecologist and if test is positive, He/She will help you.
Please practice safe sex
, like condom as they not only protect from unwanted pregnancy but also many sexually transmitted diseases.