An ectopic pregnancy is an unfortunate situation. This can be dangerous to the mother, and is almost always fatal to the fetus. There are many variants of ectopic pregnancy, so I would recommend that you talk with your OB/GYN for you specific case.
In general, the fertilization process (where the egg and sperm meet) takes place in the fallopian tube. The egg is released by the ovary into the fallopian tube which is a passageway to the uterus. Despite that fact that the egg and sperm meet in the tube, they normally don't implant
into the mother's body until they reach the uterus (they just float down). If the fertilized egg implants outside of the uterus, this is an ectopic pregnancy.
, the one cell (egg and sperm together) divide. It develops into the placenta (the actual part attached to Mom, and the fetus itself. This is connected by the umbilical cord. As such, the ectopic pregnancy would have a placenta, umbilical cord and fetus -- all just in the wrong spot. In reality, these pregnancies often are terminated before the cells divide into placenta, umbilical cord and fetus (when it is all one collected group of cells) as the fallopian tube has such little space.
Talk to your OB/GYN for more information.