What are the causes of a late period? (See details)?

I'm not pregnant but I did notice my aunt flo was late this month and this is more of a scientific question, I moved from a house with 2 other girls to a house with a guy. I know when your around girls a lot, your periods get in sync with each other. So I'm just wondering if moving from a girl house to a guy apt would miss up my period, lol because of those hormones you put out