period

sam
Can someone answer this question?
So I don't have a mom in my life and I live with my father. My period started when I turned 12. I'm currently 3 months away from  turn 18, and Ive been tracking my period and my period is very wacky. It never starts when it's suppose to or end. Im trying to track it before I lose my virginity. Any reasons why my period is so off?