you won't.

even if your periods are very regular it is impossible to know without charting or hormone testing when ovulation occurs.

unless you are a very dedicated charter who religiously charts cm, basal body temp and other signs then you have no way of knowing when you ovulate.

If you are a dedicated charter then you may be able to tell when you ovulated after the fact.

should i know by symptoms of ovulation? i bought an ovulation kit so hopefully can help tell me. all 3 day i've been having lil cramps on and off all day i don't know if that means anything.
Laura

Your best bet to help predict ovulation is going to be the opk and charting. Charting will let you know that you have ovulated while the opk will let you know that ovulation is comming. Good luck and keep us posted.