i had unprotected sex on saturday december 11,2010 i got worried and sunday i took 4 yaz birth control pills on sunday and on monday i took the next choice pill and 2 weeks later on the 24th of december i came on my period this january i havent came on my period this whole month and still not i took 2 pregnacy test and they were both negative i dont know what to do.... please any advice or helpppp