I want to know what is the expected of ovulation.so that fertilization can occure?

Estimating ovulation can only occur a handful of ways. Many women ovulate around the middle of their cycle. For example, if you average a 28 day cycle, you could ovulate any time between day 11 - 14. However, that is not a guarantee. Both times I fell pregnant, I ovulated on day 9 and day 10.

OPK's (Ovulation predictor kits) are sold at many stores, they are helpful in many cases. Other than that, there is a technique of monitoring cervical mucus and taking basal body temperatures. Anything else is just a guess.

To learn about temps and cervical mucus, I recommend a book called "Taking Charge of Your Fertility".

They are somewhat hard to track, but yes you will need a kit and be taking temp daily to know the most fertile times.