How long is LH surge detectable?

Natalie • July 21 💚 Feb ’20 💙 March ‘18 💙 Dec ‘15 💙🧩 4 miscarriages 🌈
I think my body is preparing to ovulate 🎉
How long is the LH surge detectable? I've been taking an opk every day at noon. CD 12 & 13 both look positive to me.