Why hasn't my period come?

I was supposed to start sometime this week and I'm cramping like I'm starting and when I wipe there's the tiniest trace of blood, but still nothing. One of my best friends just passed away a week ago Saturday and I was extremely suicidal so my boyfriend took me to the hospital. I had to have my blood taken and give a urine sample. They would've told me if I was pregnant and they didn't say anything. Is it because of the extreme emotions and stress my body is going through that may be messing my period up?