How do you tell the difference between a miscarriage and a threatened miscarriage?

A miscarriage means you have definitely lost the baby, there is usually lots of cramping and clots. A threatened miscarriage means just that, you are still pregnant but may miscarry in the future. Any spotting while pregnant can be called a threatened miscarriage and many women go on to have healthy babies. If you still have signs of pregnancy like swollen and sore breasts it is probably just a threatened miscarriage. Most doctors will order an ultrasound scan to tell for sure. I should think that a blood test (Quantitative HCG) would be more reliable than ultrasound. Levels are decreased in the case of miscarriage, threatened &/incomplete abortion, & if the fetus is dead.