Ever since I got my first period, I have been regular. That is with the exception of when I was on depo and then now. At the beginning of the month I had my period which lasted about three or four days, which is normal for me. Then today, I started again. This is not normal for me and it's the first time that this has happened. It has me concerned. Can anyone explain to my why this is happening. I know that everyone is different, but maybe give me some answers as to what causes this to happen would even be helpful. Thank you.