Irregular cycles and trying to get pregnant

I been married for 4 years I only been pregnant one time back in 2012 and I had a miscarriage and I been trying for 3 years now and my cycle is very irregularly I going 7 months and even a year without a cycle and i dont know when i am even ovulating and me and my husband really want kids.....I really need help any advice!!! PLEASE HELP!!!