Ovulation is the release of a mature egg from an ovary. It occurs at about the 14th day of a woman's menstrual cycle. The first day of your period is day "one".
Every woman is different, so...
The peak in LH triggers ovulation. "During ovulation" is only an instant in time, so it's not really separated from "before ovulation." When LH peaks, ovulation occurs, so if I had to pick, I would...