Birth Control

Not wanting to have sex anytime soon but I’ve been looking at different forms of birth control for in the future! What’s the most least painful but still very effective form of birth control? A year ago my sister in law became pregnant even though she was on birth control AND she made him wear a condom… Got me questioning things now!! 😫 but I don’t want to go through the pain of getting an IUD (I have a huge fear of medical prosecutes and a really low pain tolerance)