it takes the average couple about a year to concieve. sometimes stress makes it even longer.
when your stressed your thinking of other things rather than what your doing.
try relaxing, doing things that make you happy, or see your doctor and talk to him or her about what other things you could be doing to get pregnant, maybe if you explain this to the doctor he or she could recommend something for you.
But dont stress, let nature run its course, it will happen.