Birth control pills contain either progestin or a combination of progestin and estrogen, hormones that help thicken the mucus at the cervix to prevent sperm from reaching an egg and, in most cases, even stop ovulation. While doubling up on these hormones may make you a little nauseous, there's no harm in taking two pills at the same time, Renee Wellenstein, DO, a board-certified ob-gyn, told POPSUGAR.
That said, depending on the pill you missed, you may not need to take it at all. "Typically, the last week are sugar pills, meaning they contain no hormones," Dr. Wellenstein said. "So, if one of these is missed, it's no big deal." However, missing a pill earlier in the pack can make your birth control less effective at preventing pregnancy. In that case, use a condom or another backup method just to be safe. Exactly how long you'll need to use another form of contraception depends on the type of birth control you're on and how long you went without it — you can find some general guidelines here.
So, what happens if your pill gets crushed or falls down the drain? When a mishap like that gets in the way of you taking it, "take the next pill at the regular time and use condoms for the remainder of the pill pack," Dr. Wellenstein advised.