Answer by  
                                                                                          tamarawilhite (17883)
                                                            
                          
                          
                                                          Birth control pills are 99% effective, which means they will fail about 1 out of a hundred women per year of use. It happens. Yaz is also less effective if you skipped a pill, took antibiotics, or had a stomach virus. This will not harm the baby if you stopped by third month.