The purpose of this study is to learn whether women who use progestin-only methods of birth
control such as the contraceptive implant (Implanon), the levonorgestral-releasing IUS
(Mirena), or depot medroxyprogesterone acetate(DMPA) will experience weight change compared
to women using the non-hormonal copper IUC (ParaGard).
The investigators primary hypothesis is that users of DMPA will gain excess weight and
increase their BMI above the copper-IUC users; secondarily, the investigators will compare
users' data in the LNG-IUC and ENG implant groups to the copper-IUC group.