What Causes A Delayed Menstrual Period With Negative HPT?

i was supposed to start my period sunday but i didnt so me and my boyfriend decided to have sex i lost my virginity and now im late for my period we used protection and he pulled out before he came...he filled the condom up with water and there wasnt any holes in it ....could i be pregnant? i took a test thursday and it siad negative...did i test too early?