If you want don't want to use opks to do multiple attempts at pos opk or chart etc the least stressful way is to dtd eod through to when you're sure you've oed if that's possible. So bd every 48 hours. This pattern sways strongly blue but isn't commonly suggested as eod can often be too hard to keep up. If you're quite sure dh and yourself can stay the course then that would be my recommendation. It's great for those who have a short - normal cycle (up to 30 days) but any longer and it is usually too hard. It's very important to keep to every 48 hours if you are going to do it. So if your cycle is 30 days I'd suggest dtd cd8, 10, 12, 14, 16, 18 and maybe 20 to be absolutely sure.
How long is your cycle usually?