thank you for using healthcare magic,
well it seems you missed pills in end days of cycle.. your period can be delayed because of hormonal
but i would like to tell you that o.c pills or no other contraceptive
are 100 % effective.. some minor chances are always there..
test is not very reliable it can give false result some time..
consult gynecologist and take more confirmatory test like beta hcg level or ultrasound