No, most women will O approximately 12-14 days (your LP) before AF comes. However, a LP can be like 9-16 days instead. If your LP is less than 10 days you should see your doctor as this can result in more difficulties getting pg. Your LP usually doesn't change much from cycle to cycle (1-2 days) so after you O you know that AF will come say, 15 days later, unless you are pg.
So, for me, my cycle typically goes:
CD1 - AF comes
CD18 - O day
CD 31/CD 1 - AF comes again.
So my LP is 12 days, but it takes me until CD18 to O.
You can O shortly after AF appears, but you usually don't O right before AF because it is O that determines when AF is coming. But, you can get spotting before AF. It is also possible to O more than once a cycle.
Hope that helps. If I am wrong, someone please correct me.