What Causes Stomach Cramps And Vomiting?

Hi My girlfriend and i were fooling around last night when she suddenly stoped me becuase she had this bad cramp feeling in her abdomin. This pain got really bad and severe. It got a bad she votmited and could barley stand up. I think she could possibly have an ectopic pregnancy. This lasted for about an hour, and she hasnt had any problems since. She said when she first felt the pain, it shot throughout her entire body. Any ideas? Thank a ton. Andrew