Hi mamsh! Honestly, kahit walang missed pills, hormonal changes from any contraceptive can cause delayed period, tiredness, at temperature changes, totally normal side effects, pero kung nag-worry ka talaga buntis ka or something else, please go see your doctor para ma-check lang for peace of mind, okay? A few of my mum friends also experienced similar symptoms when they switched pills, at nalinaw lang lahat after a proper check-up. Don't overthink na lang muna while you wait for your appointment, stress din yan nagpapahaba ng period sometimes!