Lh surge

I caught the surge on Sunday at 10am then I tested Monday at 8am and it was still there then I tested at 10am and it went away. I used (Clearblue digital ovulation test) But my question is do you ovulate as soon as the Lhasa surge is gone? On the the package it says you will ovulate 24/36 hours after the lh surge and My surge lasted 24 hours.