p.s. -- A friend of mine began her periods when she was 8. Don't worry, you're normal.
Try not to worry, sweetheart. Just tell your mom that you need some "female supplies," and she will know what to get for you and won't be odd about it.
Yes it sounds like you started your period. If you have females who have periods in your home, check the bathroom for pads. If not you can layer toilet paper in your under wear to catch the blood. You will need to get pads though as toilet paper wont hold very much blood and you will have to change it quit often. You could also fold a wash rag up and lay in your underwear if nothing else.