AF showed up today so I am out for this month :-( Good thing I decided to wait till the 16th to test again. I think a 5 day cutoff for you seems like a good idea. I dont think that the sperm can survive for up to 7 days..what to u think? do you remember when you conceived your sons? Was it on ovulation day.? I know my son was conceived on ovulation day so the shettles theory does make sense to me.