I conceived my 2nd child using an ovulation kit- yes it worked.
I would be focusing on the before and during of ovulation- before because the sperm hang around for a little while and the during for obvious reasons. Once ovulation is over well- it's over.
Good luck if you're trying!
Here is a little tidbit you may not know. One side is more dominant than the other. I had my tubes out after my fourth child only to discover that only one side was successful so I figured I then had a 50/50 chance of getting pregnant but my nurse told me that one side is dominant (the tubes I mean)
opks worked crap for me
any of the other women who don't have "normal" cycles and can not predict ovulation AT ALL
if you have PCOS or other such diagnosis, the opks will be a terrible waste of time and money