I was trying last year for 3 months to get pregnant and nothing was happening. Every month I would get upset when I got my period. I stopped thinking so much into it. I already exercise and stay healthy, so that wasn't an issue. Most doctors can help you decide what is best for your body in order to get pregnant. Plus, it's fun trying!
My husband and I had our first in 2009, started trying again in 2010. We weren't able to conceive until this year. Our second baby is due in October!
Keep trying, stay relaxed and hopefully you'll be blessed sooner than later!
The best bet is to talk to your doctor. If your cycle is irregular it can be harder to pinpoint when you're ovulating. Diet, exercise and stress can also affect your body's ability to allow for ovulation and or conception. Keep trying and keep your chin up.