I ended my period around 4 days ago, and it's already started again. My mom is saying it may be stress, but I haven't been nearly as stressed as I usually am. Actually, the days before I has been extremely excited due to my older brother coming over (which is pretty rare), since he's the only one in my family I get along with. Is this normal, or should I be worried? I have a pretty long period (mine is 8 days...ugh), so I'm used to it starting in the month before, but never 4 days after I ended one.