Help: Im having terrible stomach problems today?

Im 13 years of age, the only medications I may take contain acetaminophen (Like aspirin or other pain killers and things) but lately i've had these sharp pains in my stomachs and it feels like my stomach is going to explode. I cant apply pressure or anything,it hurts too bad. Sometimes it gets so bad that I have to lay down . I've also had a lot more..movements . What's wrong with me and how can I fix it?