Is It Wrong To Change The Birth Control Pill Routine?

A woman is taking birth control pills, and plans to continue taking them for three months before allowing her period to occur. She has taken the pills continuously for about seven and a half weeks (skipping the placebo weeks), at which point she experiences some breakthrough bleeding. She decides to introduce her period earlier than the planned three month threshold by immediately reverting to the placebo pills, and her period ensues. By stopping pill use in the middle of a three-week cycle of pills, has she done something wrong? Following her period, can she resume taking the pills and protected, as with normal pill usage, from pregnancy?