COCPs can prevent pregnancy if the first pill is taken no later than 5 days after a woman starts menstruating. If the treatment is started at any other time in the menstrual cycle, COCPs cannot safely prevent pregnancy for the first 7 days of use. During this time, a woman needs to use other types of contraception in order to prevent pregnancy. When active pills have been taken for 7 days, COCPs can work well to prevent pregnancy. COCPs should be taken at about the same time every day.