So angry!

My periods have been TEXTBOOK for the last 6 months! I'm talking 28 day cycles. I would have been willing to bet $1,000 on the day my period was going to start! And it just stopped! As of now I'm 6 days late. I took a pregnancy test 2 days before my period was supposed to start because I slept the day before for 19 hours straight! I haven't taken another pregnancy test since my missed date because I'm honestly afraid to! If it's negative then that means my periods are irregular again. I'm not so sure I can handle that kind of disappointment.