Preseed.

Ladies first thing, what are your experiences with preseed? Second thing, my ovulation is always off to what my calendar predicts, so since preseed is kinda expensive, will it work if i only use it as my opk’s are darkening? I’m afraid to use it during my “predicted fertile week” because last month I ovulated a week later than predicted. We’ve currently been just using it as regular lube without the applicator, but plan to use the applicator when my opk’s are almost positive / positive.