How long does a typical LH surge last?

Alexburtonx

Hi ladies, just curious as to how long LH surges typically last, first time I’ve taken an ovulation test was 48 hours ago and it was positive, just taken another one now and it’s still positive, very clear two dark lines. I’ve had tests for PCOS years ago but came back inconclusive so I’m not sure if this is the reason it’s positive or if it’s possible for LH surges to last this long, thanks