missing period??

i’ve been on the pill for four years, im currently taking beyaz. i know some women don’t get a period but i always have gotten mine. i was due three days ago but i still don’t have my period. my boobs hurt and i’ve been really emotional like i typically am when i’m PMSing. i took a pregnancy test yesterday and it was negative. is it possible that i just start skipping my period? i’m supposed to get an IUD in next month and i have to have my period for that so i’m just a bit confused and worried