Is having twins hereditary?

This is what I am wondering. My grandfather was an unidentical twin. His twin brother never had any children and the only grandchildren he had were me and my cousin. My cousin has already had her first child which was a boy. She tend to take after my grandmothers genes. While me and my mom take mostly after my grandfather is was the twin. I am my mom's only child and she says she always heard that having twins skips a generation and I have a good chance of having twins. Is this true? If so, what exactly are my chances of having twins?