Period Delayed By 3 Weeks And Worry About Pregnancy

Patient: I am 3 weeks delayed i already take pregnancy test with about 5 times.. but it is negative.. but im still delayed am i pregnant?My boyfriend and i had sex. but i don’t remember when it was. when i ask him if he withdraw it inside my vagina and then he said he did not. is it possible to get pregnant if he withdraw it outside? by january 8 2012 should be my 2nd period but i am worried if it is still delay. what should i do madaam ?