This study aims to test the effect of Doxycycline in treatment of uterine bleeding during the use of injectable contraception that contains one hormone "progesterone only".

Inclusion Criteria:

1. Women under DMPA contraception for at least one month.
2. Accept to participate in the trial after receiving adequate information about the trial including information that she is a part of randomization comprising the possibility of receiving new treatment for bleeding or inactive ingredients.
3. Women's ability to keep an accurate menstrual diary for the study.

Exclusion Criteria:

1. Lactating women for the fear of the effect of tetracycline on the breast-fed infant.
2. Patients with already diagnosed local gynecological abnormality.
3. Women receiving treatment for bleeding within the last one month.