Trying to get pregnant after being on birth control for years

I've been on birth control since I was 14 because my cramps were so bad. I'm 22 now. I'm in a very happy loving relationship and my boyfriend and I are constantly talking about having a baby. I stopped using birth control so that we could start trying but I've had no results. Does anyone know how long it usually takes to get pregnant after being on birth control for so long?