Most women reach their peak fertility rates between the ages of 23 and 31. After that point, fertility starts to decline in most women. At the age of 30, healthy, fertile women have a 20 percent chance of conceiving during any given cycle. That doesn’t mean that 30-year-old women only have a 20 percent chance of becoming pregnant in general; it simply means that 20 in 100 women will become pregnant within the first cycle of trying; 80 others will have to try again for the next cycle. So, 35% chance on the most fertile day means that you have 35% probability of conceiving during that cycle. That's why it becomes important to keep tracking the fertility to increase the odds with every cycle.
@ursulatolver: Age is also an important factor when it comes to conceiving naturally faster. You can start tracking your ovulation time on Ela and schedule the baby-making sessions definitely during those times. It will increase your chances to conceive every month. If you are below 30 yrs, then you can try for another 7 months before going to a doctor for any fertility check-up.