The key to getting pregnant is in understanding your cycle and the time of greatest fertility for you. In one cycle, within one period, there are4-5 days in which you are most fertile and you need to use this period. If you have a regular cycle, then the 14th day before your next period is your ovulation day, and your most fertile days will be from 1 day before that to 3 days after.
The easiest way to do that is the basal body temperature method. Take your body temperature everyday early in the morning after getting up. Normally it should be between 97-97 degrees, but on the day of ovulation, you will have a 1 degree rise in BBT. This is the time when you should try the most to have the baby.
Another important thing that you can do is to buy a Ovulation testing kit, this is available in any pharmacy. With this you can test your cycle to find out when you have your ovulation. This is the period when you are most fertile.
During the fertile period:
Have sex once a day. More than this can also dilute semen count.
After sex, lie on bed with the legs bent and with a pillow under the pelvis (so that the semen flows inwards so to speak) for about 30 minutes.
Avoid alcohol and smoking as far as possible at least during the fertile period.
Have good nutritious food.
Avoid extra exertion - while trying for fertility it is better to avoid doing cardio exercises like cycling and jogging during the second half of the cycle.
These steps will help, however if you do not have you should show your doctor.