**Core Concept**
Combined oral contraceptive pills (COCs) contain a combination of estrogen and progesterone, which work together to prevent ovulation. A single missed dose can disrupt this hormonal balance, potentially leading to a brief window of fertility.

**Why the Correct Answer is Right**
In the event of a missed dose, the patient should take the missed pill as soon as possible, ideally within 12 hours. This allows the hormonal balance to be restored, minimizing the risk of ovulation and subsequent pregnancy. If more than 12 hours have passed, the patient should use an additional form of contraception, such as condoms, for the next 7 days to ensure protection against pregnancy.

**Why Each Wrong Option is Incorrect**
* **Option A:** Taking two pills at once will not compensate for the missed dose, as the hormonal balance is not restored by simply doubling up on medication.
* **Option B:** Using emergency contraception, such as levonorgestrel, is not necessary in this scenario, as the patient is already on a combined oral contraceptive pill.
* **Option D:** Discontinuing the contraceptive pill altogether would leave the patient vulnerable to pregnancy, making this option impractical and unsafe.

**Clinical Pearl / High-Yield Fact**
When counseling patients about missed doses of combined oral contraceptives, it's essential to emphasize the importance of taking the pill as soon as possible, ideally within 12 hours, to minimize the risk of ovulation and subsequent pregnancy.

**Correct Answer:** C.