How Can Irregular Periods Be Treated?

Hello, I am 33 years old, 5 5 tall and weigh 9 1/2 stone. I havent had a normal menstrual cycle for 7 years now and wonder if there is anything I can do to restore it. I have had 2 children in that time and only stopped breastfeeding the second one 4 months ago. Both times I got pregnant with the help of clomifene and hcg injections. My periods had been virtually non existent for 2 years before I started this though, and I had nothing naturally in the 2 years between pregnancies. Is there anything you can advise? I am not hoping for any more children but would like to have a normal cycle again. I do have a hernia which can cause discomfort but not too much problem. Would this have any effect on it at all. It is about an inch above my navel.