Hi Nisha, if you took the ipill within 72 hours of unprotected intercourse
and now, inspite of delayed periods, your pregnancy
test is negative it is highly unlikely that you are pregnant. Ipill contains high levels of female hormones which though prevent conception ,also cause hormonal
imbalances which lead to alteration in the onset of periods ,either causing it be early or delayed as in your case. I suggest you take hormonal pills like Regesterone
to induce withdrawal bleeding and your cycles will regularise on their own.