I had sex in the start of feb and took an ipill and got chums on my regular schedule that month (6th feb) by haven’t got periods this month, is this because of the pill??

I also had sex on the 24th this month and and took a pregnancy test twice that came out to be negative, it’s been 11 days post my supposed-to chum date, why am I not getting periods yet?? What do I do??