Taking two birth control pills in one day is generally safe and wont have any long-term health effects. However, it may cause some short-term symptoms such as feeling slightly nauseous or having some vaginal bleeding. If you accidentally take two birth control pills in one day, you should continue taking the rest of your packet as normal at the same time you usually take it each day. You dont need to seek medical advice unless your symptoms are severe. If you miss a pill, take it as soon as you remember, even if that means taking two pills at once, and take your pills with food to avoid feeling nauseous. Its important to continue taking the pill at the same time each day because some types of pills are only effective if taken every 24 hours. If youre worried about pregnancy prevention, you might consider using a backup method of protection, such as a condom, for at least a week after the slip.