Fertility problems?

I was in a relationship for a year and 7 months we started having sex in March of 2014 and I got nexplanon November of 2014 till June/July 2015. We hardly ever used condoms. A few times from March to November he didn't pull out. And then after I had it taken out in the summer till till about October he never pulled out. We were very careless I never got pregnant. Why? Is there something wrong with my fertility?