There are two kind of general ideas that get floated that i have heard of

The first is to have sex everyday for three days from the first positive OPK but you need to have had sex about 3-5 days before to "refresh the sperm"

The other is to only have sex every second day, that way you arent wearing out yourselves and there is still fresh sperm being produced without lowering the sperm count. This is done basically roughly the week you are due to O the thought being there will already be sperm there or on its way within 24hrs.

The choice is yours, I am about to finish my 6mth of ttc have tried both methods for a few months but still havent been lucky and I am starting to think that luck plays a good part in all of this.

Good luck to you, it is hard "having to DTD" try to relax and make it more about your affection for each other rather than a baby making mission.