If you are not having periods, you are not ovulating. You only get a period if you have ovulated. Obviously you and your husband can enjoy yourselves and hope to catch the first post-breastfeeding ovulation when it happens, but if you are serious about conceiving you will probably need to cut down on breastfeeding. I breastfed for 14 months and I think I got my period back around 12 months. As soon as you get the first period, you can start tracking your cycle, but you'll probably need a few months to pinpoint where you're at.
My two cents would be to keep nursing now and be patient. Get the book Taking Charge of your Fertility so you'll be ready to chart when your period does return. Your period will probably be back in the next few months, as your son starts to eat more solid food and nurse less. Many women can continue nursing while pregnant, too.
Good luck,
B.