Wish I could get a definite answer🤔😔

•Ash•
I don't know wtf is wrong with my body lately. I was supposed to start my period 4 days ago (since it's after midnight for me, it's now day 4). But nothing. So sign of af, no *real* line on a hpt: nothing. This has never happened to me before. Last time I was this late, I was pregnant and got a super positive on the last day of what was supposed to be my period, aka day 4. 
My cousin said it could be from stress, but I've been in extremely stressful situations before and never missed a period, wasn't even late! 
I don't know what to do🤔🤔 Any helpful hints from anyone?😁