LH Surge Testing

Ka

I know they say to test twice a day when looking for the LH surge.. but my surge is now two days later than usual (with very consistent testing). I’m worried I will miss the surge and want to test as frequently as possible (without wasting too much money). What is the quickest you’ve gotten a positive LH surge result? For example, fours hours would be if you took a negative OPK at noon but a positive one four hours later.