i was supposed to get my period on thursday and now its sunday. my period is usually pretty regular and comes when its supposed to and i havent missed a period in a couple of years. i had protected sex on november 28th and i got my period in december like i was supposed to and it was a normal period and it came the day it was supposed to come. i still havent had my period this month and i was wondering what could be the cause ?? i’ve heard of women still getting their period while pregnant but i just feel like thsts not the case for me. im 15 turning 16 in a few days. please help.