birth control

I started my first pack of birth control a few weeks ago. i’m now on my sugar pills which is the week where i’m supposed to have my period. my pills are meant to lighten my period but i haven’t gotten it yet. i had sex but we used a condom so i don’t think i could be pregnant but is it normal to miss your period the first month? i was on nexplanaon last year (got it removed) and i missed it the first month but then got it back the next month so could it just be the way my body just reacts to birth control?