Sharp pains from inside stomach pulsing out

[Dommy08]

My 15 year old girlfriend was laying in bed tonight and she had her hands on her stomach when she felt something literally poke out of her stomach into her hands. She took a pregnancy test the night before and she's negative. Then for the next half hour she started feeling pulsing sharp pains in her stomach that i could feel when my hand was on her stomach. They reached from lower abdomen to her hip and up past her belly button. Please answer and thank you for anything.