hello , i am on birth control (the pill)

so i ALWAYS have a period, every month, at the same time, bc of the placebo pills of course ..

however I resume on my new pack tomorrow (the actual pills) and I have not had my period yet .. the day I was supposed to start, I bled a little bit so i put a tampon in assuming i was starting .. the tampon was dry when I took it out a few hours later & i haven’t bled since ..

does anybody know why this would be happening? i have been more stressed recently which i know can cause late periods sometimes, however i wasn’t sure if that was the case in this situation especially since i start my new pack of pills tomorrow .

any suggestions or advice ? has this happened to anyone?