Is a lady (female) only fertile for 6 days out of the month?
If you want to be completely literal a woman is only fertile for 24 hours, since conception can only take place between within the first 24 hours after ovulation, since thats the maximum amount of time an unfertilized egg can survive. But sperm can survive up to 7 days (though 3-5 is the normal), inside the uterus/fallopian tubes waiting for the egg to be released). Meaning that a woman is normally fertile from 5 days before ovulation til one day after (so a total of 7 days), but with long living sperm a woman can potentially be fertile from 7 days before ovulation til one day after (so a total of 9 days).