PLEASE help.. was my pregnancy test result wrong?

on the weekend of october 30th my fiancee and i had unprotected 3 times.. im not on birth control.. and on the 12th of this month i was suppose to get my period but sometimes it will come on the 14th and it still hasn't came so i took three urine pregnancy tests and the first one didn't work and the second two were negative but i drank lots and lots of water before the test.. before i knew it could dilute it.. what do you think.. advice? should i wait and retest?