A condom because not only does it not change the body's hormonal system it blocks any seminal fluid from entering the vaginal opening. Little fact: A condom is much better than the pill because when a person pees that excreted fluid will be released back into the environment also affecting fish populations. So when doing it, your best bet is using a condom because the pill ruins the environment and disrupts fish populations because they are unable to impregnate during mating seasons, which also affects us because we need more fish for the markets.
Heh, sorry for the long answer, I care for the environment.
