Suggest Treatment For Irregular Period After Treated Ectopic Pregnancy

I had an ectopic pregnancy back in may as a result of taking the morning after pill (i was having a break from my usual contacpetive pill but unfortunately the condom broke). I had an emergency laparoscopy and had my right tube removed (ovary still intact). I went back on the pill about a month after the operation but have not had a proper period since, nothing at all for the last three months. I have been to my doctor and been told it is just my body trying to rectify itself or could be stress-related but I am beginning to worry that there is something wrong as I know I am not pregnant again. Please help.