The purpose of this study is to assess acceptability and side effects of a low-dose injectable contraceptive formulation which is delivered under the skin (subcutaneously), as compared with injectable contraception delivered into the muscle (intramuscularly) among adult HIV-positive women who attend mobile clinics for HIV care and wish to use injectable contraception. The investigators will also assess experiences experiences delivering these two types of injections among health care providers working within the HIV care clinics.