Q: Cervical fluid (CF) can keep sperm alive in the cervix for how many days?
A: Three to five.
http://www.katiesinger.com/singer.iq.htm
In reply to:
After ovulation, an egg lives (and can therefore be fertilized!) for about 24 hours (but can live up to 3 days.) Sperm can live for 48 to 72 hours after ejaculation in a hospitable in a warm and moist environment. But they have been known to live for up to 5 days.
http://www.uottawa.ca/health/information/contraception-natural.html
You can do some research. but the average is 3-5 days where ever you look.