Fertile or infertile?

Briana • Work, live, and play.
Alrighty, we aren't trying to get pregnant. So we track my fertile days very closely, yet with my period being kinda short than long early than late. Kinda doesn't help, yet even when we do it on my most fertile days with no spermicide or pulling out. I've lucky never gotten pregnant, which still makes me wonder can there something wrong with one of us?