Fertility Issues

My bf & I have been together about 4 years now. Every since we met and started having intercourse he’s always ejaulated inside me. There has also been guys in the past who did as well. After our first year of being together we started talking about having a baby. We tried & tried, but I always got my period. We’ve been trying for almost 3 years now, and I just don’t understand why I haven’t gotten pregnant yet. I’m 23 years old, no health issues (at least not that I know of), and he’s healthy as well. I was on birth control pills & the depo shot for years, and I’m not sure if that has caused issues. I really need answers because this has really become depressing for me😭😭