hi. I had unprotected sex last april 26, 2013. he did withdrawal and im pretty sure i wasn't fertile that time because my last period was april 6, 2013. I took nordette 4 hours after doing the deed, 4 pills at the same time and another 4 after. until now, may 2, 2013 i still dont have my period which is supposed to be the date i should have it. what is the meaning of this? im stressing out and getting paranoid. :(