Could The Mood Swings, Morning Sickness And Increase In Appetite Be Due To Pregnancy?

I just to ask if could I be pregnant? I have my period last Oct.18,2011 and now my period was late within 1 week,but starting Nov.2 I always feel moody,I'd always taking a lots of foods and fruits that i want,I have my morning sickness which is I feel bad and always vomiting, and everyday I'd go to my office I always get tired which is my lower back hurts and i always feel sleepy,but yesterday Nov.24,2011 I have my period but it doesn't looks like my regular menstruation w/c is red blood, yesterday it was color brown like a mud,what happen to me?