Originally Posted by
atomic sagebrush
It does a teeny bit but for most people, by DTD every 4 days, you really DO only have one viable attempt in the fertile window. The fertile window is really a lot smaller than you think. Practically speaking, it doesn't last much more than 3 days and most of the time those every 4 days attempts end up being something like 6 DBO and then 2 DBO - 6 DBO all the sperm will have died off leaving you with one real attempt 2 DBO
I am not here to try and argue or convince you into doing it a certain way. All I can say is that if OPK aren't working, then the every 4 day method is next best thing.
The reason why you'd continue to have attempts after you think you ovulated is because IF you did ovulate, your egg will be dead or fertilized by then anyway and all the attempts in the world make no difference, and IF you didn't, then you're still covered.