SIL baby shower

My MIL invited me to my fiancé brothers baby shower. And i dont mean to be rude or jealous but i am. Me and my fiancé are suppose to be getting married and trying for a baby but everythings going wrong. I put the wedding on hold fo reasons and the baby making after trying for a year. To see these happily married couples with families just kind of gets me down. So i dont want to go but would that be rude not too?