My suggestion is just because it would get very expensive if you wanted to use it this way for a few cycles.

If you got a positive on cd15 you wouldn't have ovulated until late on cd15 or cd16. So the preseed on cd11 wouldn't have been any benefit. The cd11 swimmers would have been a bit washed up by ovulation day! Do you know what I mean? The preseed on cd15 and cd16 would have helped get those swimmers to their destination!

So, you are absolutely right. If you don't know the timing of your ovulation you would need to use it potentially for a week. However, if you use opk's to check when you expect to ovulate this would mean you would narrow down the preseed useage to a couple of times.

I just wouldn't like to see women using it for a few months at 5 applications a month. Very exy!