Why can't it happen for me

I started having sex when I was sixteen years old with my high school boyfriend, sex isn't one of those topics that my parents discuss with there children, so at that age when I started to have sex I didn't know anything about contraceptives, my boyfriend was three years older than I was, we spent four years together and I never got pregnant, I didn't think much of it as I wasn't ready to become a mother, but within the last year of our relationship things became straineous as he started talking about having a child been that he is the first child for his mother and his younger brother girlfriend was pregnant. It was at that time that I became conscious of the fact that I haven't been using birthcontrol and I didn't get pregnant. I visited a gynaecologist and related my story, I was sent to do a multiply amount of blood test including STDs, HSG and a ultrasound.All the test came back negative except for the ultrasound which showed that I had a cyst on my left ovary, I was given medication and was told that it's too small to be removed surgically. My boyfriend also had to do some test which shows that his sperm count was low. I was told that even though I had the cyst I can still get pregnant. My boyfriend still blamed me for not been able to have a child which result in the end of our relationship. I am now married to a wonderful man and we are having the same experience (my husband is fertile and I no longer have a cyst, I see my period every month). What can we do to increase our chance of having a baby? Please help me!!