Thank you for your question.
Generally speaking if you and your wife are in good health and she has regular periods you have a 95% chance of conceiving within two years of marriage with regular intercourse. You don't say how long you have been trying for a baby and what your general health is like.
If you are still concerned you should consult a fertility specialist who will test both of you to make sure that your sperms are healthy and adequate in number and that your wife is producing eggs correctly. They will interpret the tests and give you correct advice to proceed from there. This may even be to do nothing other than take a vitamin called folic acid to help with the baby's neural tract. You may find that this all takes time. Some tests for your wife are related to her menstrual cycle so a month here and there is quite common time period to get tests done. So please note that things don't always happen as quickly as you would like them to. Many times the anxiety to conceive can cause stress which disrupts ovulation and can even cause a spasm of the muscles in the tube preventing a pregnancy even if all tests are normal. When you are trying for a baby it is very important to take folic acid and remain in a positive expectant state of mind free from worry, anxiety and fear. Please ask your doctor to recommend a simple book or leaflet to guide you as you try for a baby. It will help to answer a lot of questions and dispelled anxiety.