It takes the average, healthy couple 6 months to get pregnant, a year is considered totally normal if you are under 35. Most likely you are having sex at the wrong time in your cycle. From the time your period stops you should have sex every other day to help catch that window for ovulation. If you start tracking your cycles (taking temperatures, marking your calendar, paying attention to cervical mucous texture, etc.) it will help pinpoint when you should be having sex. Chances are good if your doc cleared you both of physical problems that it's just a timing thing. Good luck!
it could just be a matter of timing. your body is only capable of being fertile a couple of weeks out of the month. if you get an idea of your body's timings it could help with the attaining a pregnancy.
it could also just be a matter of low sperm count in the partner.
it could be something as simple as these things. i don't think there is anything major going wrong in your situation from what i have read,