It can be due to infection, cycle irregularities due to hormonal imbalance or it might be implant bleeding. Get pregnancy test. If the test is negative then visit a doctor for differential diagnosis and appropriate treatment.
When I Pee And Wipe I Have Spotting Or Light Bleeding . What Is That?
I would say that you aren't very old, and that you are starting to get your cycle. I would talk to your mother, and if she isn't there, maybe at work or something, then call her and tell her what is going on. If you can't talk to her, maybe then you can talk to a grandmother, or one of your friends until your mother gets home. Getting your first cycle can be scary, but don't panic! Go into the bathroom, and use a pad to line your undies with, it might be uncomfortable for a while, but be assured, you are going to be o.k. Hope this helps, good luck.