What Does Missed Periods After Having Unprotected Sex With HPT Negative Indicate?

Hello i had sexual intercourse on Dec29,2010 but didnt get Plan B. On Dec 31 i had sexual intercourse again.Until Jan1,2011 its when i bought Plan B. i took it at 6:30pm and i was supposed to take the second at 6:30am but i over slept and took it at 7:15 am (45min late)its been 17 days that i took Plan B, and i still have not got my period i took a home pregnancy test 2 days ago and it was negative. What are the chances of me being pregnant or not?