When your lh surge drops is that because you have now ovulated or does it drop again after your surge before ovulation occurs?

Yes: No one who knows exactly how long lh surge last. It definitely lasts at least 36 hours. In most women. .We know from in vitro fertilization ovulation occurs somewhere between 36 to 48 hours after the lh surge. It is best to have relations with your partner the day of your lh surge and the next day. We know that it is best if sperm are there before ovulation.