my girl friend uses Tri-sprintec. she took her pills like required everyday. now there is 2 blue pills left in the pack before she has to begin the white pills for the period.(saturday) well the night when she took 1 blue pill(one blue pill left) we had unprotected sex. now we are worried that it was to close to the time that she has to start the white pills that the blue pills will work.would she not have the chance to b pregnant? but is monday and she started to take the first white pill last night.please help