Anyone ever hear of this??

I’ve read about it and I am trying it this month after my miscarriage in January

It’s says to start BD on CD8 and every other day until you get a LH surge then BD the next 3 days.

Last night was our night off so tonight we would BD. I got my surge today. So my question is: is it ok that we didn’t BD last night? Bc I’m following this I know usually the night before ovulation is most important but my OPK test was so low last night!