Well, that is if you believe Nas' former girlfriend and baby mama, Carmen Bryan. She did a question and answer session with her fans on Twitter a few days ago, and spilled everything. She claimed the feud between Jay Z and Nas started after she dated and got pregnant for Jay Z. She said she later lost the pregnancy. The feud between Jay Z and Nas (from 2000/2005) was one of the most followed feuds in hip hop history.