Ovulation Confusion!!!!!

I started to show an "almost positive" on ovulation stick on the 22nd. I had a positive yesterday on the 23rd and felt major ovulation cramps around 2 pm. Today, on the 24th, I tested again and the ovulation stick is still positive. Isn't LH supposed to decrease once you ovulate or is it possible to surge for more than one day? The below pic is from today.​