Normally, after fertilisation, the egg becomes a zygote and develops in the ovary for a certain period before migrating from the ovaries to the uterus through the fallopian tube. In the uterus, the zygote gets implanted in the uterine walls and develops into a full-grown baby gradually. An ectopic pregnancy is one that grows outside the uterus. An ectopic pregnancy can be life threatening because as the pregnancy gets bigger inside the tube, it can burst (rupture) causing severe pain and internal bleeding.