Is It Normal To Have Irregular Periods After Having A Baby?

Hi Doctor. I had delivered a baby boy on May 10, 2009 from a cesarean delivery. I am really worried as I am not yet having my periods. I wonder why still after 14 months I am yet to have my periods back. Please advise me Doctor as I am really concerned about it. From the delivery I am not indulging myself for intercourse with my husband for the fear of getting pregnant again.