ive been told sperm can live up to 5 days
It's the life of the sperm plus how early you ovulate. You sound safe but not if you happened to ovulate early that month. My thought it that it would be about five days too early to get pregnant, even if the sperm lived the longest possible time, because women rarely ovulate that early unless it was an unusually long period. Starting counting the cycle from the first day you start bleeding, ovulation is supposedly on about day 15 of your cycle.