I know sperm can live 3-5 days in a women, this is also if she is on birth control. My question is how long can the sperm live in the first week of just starting birth control? When does the cervix become an unsuitable environment for sperm? If the pill is not taken correctly within the first 2 weeks of just starting birth control can this cause the environment to still be safe of sperm to live until an egg passes? (saying one incorrectly takes pills: if multiple pills are missed at a time)