Friend monique symptoms and conditions

hi me and my friend monique took these birth controll pills called "YASMIN" and we feel pretty sick. we dont even have sexual intercourse and we still took them and they were her sisters. we dont know for sure if the stomach ache (nauseaous feelings in our stomach) is from the birth controll that we took.. if you could please tell us he answer and how serious this is, we would very much apreciate it. Thank You..
Holly