haven’t gotten my period

i don’t normally post on here but i need some input. i started a new birth control so that i get my period every 3 months. i have a boyfriend and we have sex. i was supposed to get my period 3 days ago and haven’t gotten it. i never had a problem before starting this new pill. i’ve been on the pill for 3 years. i’m starting to freak out a little. but it may just be because i started a new pill. need some advice