Tuesday lunchtime - almost positive opk Wednesday AM- peak reading on fertility monitor (clearblue) Wednesday lunchtime - negative opk Wednesday PM - completely blank opk So I figures my surge was detected somewhere between Tuesday afternoon and Wednesday AM (before the negative opk wednes lunchtime). So the negative opk wednesday tell me the surge is over. IF ovulation occurs 12-36 hours after the positive opk (IF i re-did opk tuesday afternoon-evening)... I an therefore due to ovulate sometime between wednesday AM and thursday AM right? So would you count Wednesday as ov day, thursday 1 dpo ? We DTD Saturday, Wednesday and last night (thurs). Are we likely to have missed it? X