Haven't had my period

Once I got cleared I started birth control for the first time ever my prescription lasted 6 months into postpartum i didnt have time to get a new prescription. Well 8 months later now I'm a year and 3 months postpartum and I haven't gotten my period. I am not pregnant I have taken a pregnancy test so I really don't know whaat is going on with my body, no breastfeeding.