hi doc! i am worried now.i start using my 21 tablet pills at the forth day of my menstrual period that was july 20. and i have my first contact last july 22 while taking pills. i finished the last tab last aug 9, but until now,i dont have a period. .what shall i do,doc? i have a contact with my boyfriend several times now because i thought it was safe now. . pls. advice me,doc! thank you. .