desta, Gedamnesh; assefa, Nega  Major Advisor (PhD); oljira, Lemessa  Co Advisor (PhD)
 (Haramaya university, 2018-05)
Background: Happening of pregnancy while a woman is using a contraceptive is termed as
Contraceptive failure. It is a major source of unintended pregnancy, in most cases associated
with typical inconsistent and/or incorrect ...