Lower right side pain. Any ideas?

I am a female , 13 years old , and I have been having mild and steady cramps on my lower right side. I had my period two weeks ago and it doesn't feel like menstrual pains. My mom considered a bladder infection; although it doesn't burn when i pee. It is more like a strange, semi-painful feeling like a need to pee more when I go. I am really worried that it might be something worse. If you have any ideas or further questions; please say!