For the past two- three weeks, I've been having this sharpish pain in the right upper to lower side of my stomach when I'm walking around a lot, standing in the shower, stretching, and sometimes laying down. I thought it would go away after I had my period , but unfortunately it didn't. I haven't been vomiting, and I'm not sexually active. I'm 13, so I'm not quite sure on how serious it could be. Any suggestions on what I should do, or ideas on what it could be? Thank you for your time. :)