Progestogen-only pills (POPs) or "the minipill"

Combined oral contraceptives or pill

Contains only progestogen hormone, not estrogen 

How it works: 
Thickens cervical mucous to block sperm and egg from meeting and prevents ovulation
Effectiveness to prevent pregnancy: 
99% with correct and consistent use. 90–97% as commonly used
Comments: 
Can be used while breastfeeding; must be taken at the same time each day