OPK.....

So I have been using OPK and this month I had 4 high fertility days then yesterday at 5pm I tested and got a Peak +OPK so we BD last night. Then this afternoon around 4:30pm I was curious and since I had an applicator from a previous OPK box I thought i would test and see if I was still +OPK ... well it said I was low fertility today...
So does this mean my ovulation window is roughly less than 24 hours? I was shocked to test LOW when 24 hours ago I FINALLY got a Peak. Not sure if this means anything? Any insight would be awesome!
THanks

The length of time your test stays positive for, tells you NOTHING about when you ovulated. It's meaningless. You can get a negative and still have not ovulated, or it can be positive and you already did ovulate.

All the tests detect is a surge of hormones. It's your body telling itself to ovulate now. But it operates on its own timeline after that, usually within 24-48 hours. The tests just detect the hormones, which may take a few hours to dissipate or a few days. The tests don't mean ovulation, they mean surge.