I’m very new to this all and I’m wondering how long after ovulation should the OPK strips not become positive anymore? I heard it was 36 hours... However I ovulated near or on Christmas <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> and I took a opk for shits and giggles also because I don’t have any HCG Strips and it’s still a faint line (which I know isn’t positive) but shouldn’t it go away if I’m closer to af?