why is my partners period late?

my partner and i have started having sex recently and we have never had unprotected sex. we have only done it 3 times in 2 weeks. twice on one day and once on the first day. her period is now 2 weeks late. im absolutely terrified that she might be pregnant. she says she is 90% sure that she is not pregnant. i dont know why im terrified because i didnt ejaculate inside her and i used a condom. the condom never broke. HELP!!!!!!!!! :-( :-(