Can you still ovulate if you haven't had your period in 3 mo

I haven't had my period in three months. I am very irregular always have been. I have had difficulty finding when I am ovulating because of this. My boyfriend and I want to start a family. I went to the er and recently I found out that I have an oviarian cyst about 2.4 cm. I really want to start a family now because a woman at work had to have a historectumy because of a cyst. When can I tell if I am ovulating or if I even are because of my cycle being off? :cry: