the woman up top are right..you get a white kind of slimy in a sense discharge associated with possible cramps by ovaries,headaches,nipp les may hurt,extra hornyness.Or you may not have any of these and just the discharge.
The easiest way to track if your period is regular is to figure what day your next period will start then count back 12 days from that day..then another 4.This is when your most likely to ovulate within this 5 days.Your most fertile days are 2-3 days BEFORE through the day of ovulation.
Even if you are not trying to get prego I think every woman that is able to ovulate should know when they are most fertile.
If your irregular and you want to know there is ovulation calculators that let you know..the best is on babycenter.com.Once again even though your not trying to get pregnant you can still go on and check to give you an idea..I found that sight to be the most accurate when I was tryibng to have my son.