**Core Concept**
Ampullary pregnancy is a type of ectopic pregnancy, which occurs when a fertilized egg implants outside the uterus, specifically in the ampulla of the fallopian tube. The ampulla is the widest part of the fallopian tube, and it is the most common site for ectopic pregnancies to occur.

**Why the Correct Answer is Right**
Ampullary pregnancies tend to rupture earlier than other types of ectopic pregnancies. This is because the ampulla is a relatively narrow and fragile part of the fallopian tube, and the growing embryo can cause significant damage to the surrounding tissue, leading to rupture. Typically, ampullary pregnancies rupture between 6-10 weeks of gestation, with an average of around 8 weeks.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it suggests that ampullary pregnancies rupture later than they actually do. While some ectopic pregnancies may rupture later, ampullary pregnancies tend to rupture earlier.
* **Option B:** This option is incorrect because it suggests that the rupture time is the same as that of interstitial pregnancies, which is not the case.
* **Option C:** This option is incorrect because it suggests that the rupture time is the same as that of cervical pregnancies, which is not relevant to ampullary pregnancies.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that the rupture time of ectopic pregnancies is inversely related to the site of implantation: the earlier the pregnancy, the more likely it is to rupture in a narrower part of the fallopian tube, such as the ampulla.

**Correct Answer: C. 8 weeks**