My period just ended today and I have a set of OPKs. I have read that I should have sex before I even ovulate because the sperm live for up to 72 hours. I don't think that glow has been entirely accurate before with tracking my fertile days (thanks to the Depo shot messing my business up) but when I get a faint 2nd line on my OPK does that mean I have higher levels so I will ovulate or I am ovulating? Or do you ladies just go off when glow tells you that you ovulate? And have sex 2-3 days before that.